Merge branch 'master' into fix/issue-790-slice-a-heartbeat-policy

branch_cleanup_guard.py

@@ -537,6 +537,90 @@ def assess_ownership_record_activity(record: dict[str, Any]) -> dict[str, Any]:
     }
 
 
+# Reviewer-lease reclaim is only reachable from a non-live (expired/stale) lease.
+_RECLAIMABLE_REVIEWER_STATUSES = _EXPIRED_STATUSES | _STALE_STATUSES
+
+
+def is_active_ownership_status(status: str | None) -> bool:
+    """True when *status* denotes live/active ownership of a branch (#855).
+
+    Used to decide whether a *competing* active claimant still uses a branch
+    when weighing an expired reviewer lease for reclaim. Expired, stale,
+    released, and terminal statuses are not active.
+    """
+    return _norm_str(status).lower() in _ACTIVE_OWNERSHIP_STATUSES
+
+
+def assess_expired_reviewer_lease_reclaim(
+    *,
+    role: str,
+    status: str,
+    pr_merged: bool | None,
+    owner_pid_alive: bool | None,
+    competing_active_claimant: bool | None,
+) -> dict[str, Any]:
+    """Decide, explicitly and fail-closed, whether an expired reviewer lease
+    may stop protecting an already-merged branch (#855 AC4).
+
+    An expired reviewer lease should not protect a merged branch forever once
+    its work is done and no live claimant remains. Reclaim is permitted only
+    when **every** condition below is provably satisfied; any unknown
+    (``None``) or contrary value keeps the lease protective:
+
+    - the lease is a ``reviewer`` lease (author/merger/controller/reconciler
+      leases are out of scope and always keep protecting);
+    - its status is expired or stale (never an active/live lease);
+    - the PR is proven merged (``pr_merged is True``);
+    - the lease owner process is proven dead (``owner_pid_alive is False``);
+    - no competing active claimant uses the branch
+      (``competing_active_claimant is False``).
+
+    Returns a decision dict with ``reclaim_allowed`` and, when refused, the
+    fail-closed ``reasons``. The reasons never contain secrets — only the
+    role, the status, and which condition was unproven.
+    """
+    reasons: list[str] = []
+    normalized_role = _norm_str(role).lower()
+    normalized_status = _norm_str(status).lower()
+
+    if normalized_role != "reviewer":
+        reasons.append(
+            f"lease role '{normalized_role or 'unknown'}' is not a reviewer "
+            "lease; expired-reviewer reclaim does not apply"
+        )
+    if normalized_status not in _RECLAIMABLE_REVIEWER_STATUSES:
+        reasons.append(
+            f"lease status '{normalized_status or 'unknown'}' is not expired "
+            "or stale; only a non-live reviewer lease may be reclaimed"
+        )
+    if pr_merged is not True:
+        reasons.append(
+            "PR merged state is not proven true; reclaim requires an "
+            "already-merged PR (fail closed)"
+        )
+    if owner_pid_alive is not False:
+        reasons.append(
+            "lease owner process liveness is not proven dead; a live owner "
+            "still protects the branch (fail closed)"
+        )
+    if competing_active_claimant is not False:
+        reasons.append(
+            "a competing active claimant may still use the branch; reclaim "
+            "requires no other active ownership (fail closed)"
+        )
+
+    allowed = not reasons
+    return {
+        "reclaim_allowed": allowed,
+        "role": normalized_role,
+        "status": normalized_status,
+        "decision": (
+            "reclaim_expired_reviewer_lease" if allowed else "keep_protecting"
+        ),
+        "reasons": [] if allowed else reasons,
+    }
+
+
 def assess_active_branch_ownership(
     *,
     remote: str,

control_plane_db.py

@@ -599,6 +599,35 @@ class ControlPlaneDB:
                 (_ts(), session_id),
             )
 
+    def list_sessions(
+        self,
+        *,
+        statuses: Sequence[str] | None = None,
+        limit: int = 500,
+    ) -> list[dict[str, Any]]:
+        """List session rows for restart / impact analysis (#658).
+
+        Read-only. Sessions are the process-level unit an MCP restart
+        disrupts, so the restart coordinator inventories them to compute blast
+        radius. Optional ``statuses`` filter (e.g. ``('active',)``) narrows to
+        live rows. Never returns secrets — only operational metadata.
+        """
+        clauses: list[str] = []
+        params: list[Any] = []
+        if statuses:
+            placeholders = ", ".join("?" for _ in statuses)
+            clauses.append(f"status IN ({placeholders})")
+            params.extend(statuses)
+        where = ("WHERE " + " AND ".join(clauses)) if clauses else ""
+        sql = (
+            f"SELECT * FROM sessions {where} "
+            "ORDER BY last_heartbeat_at DESC LIMIT ?"
+        )
+        params.append(max(1, int(limit)))
+        with self._tx(immediate=False) as conn:
+            rows = conn.execute(sql, params).fetchall()
+            return [dict(r) for r in rows]
+
     # ── work items ────────────────────────────────────────────────────────
 
     def upsert_work_item(

docs/architecture/mcp-restart-governance.md

@@ -0,0 +1,223 @@
+# ADR: MCP restart governance and authorization policy
+
+- **Status:** Accepted (policy effective immediately for LLM and operator sessions; enforcement tooling may lag)
+- **Date:** 2026-07-23
+- **Tracking issue:** [#656](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/656)
+- **Policy version:** `restart-governance/v1`
+- **Related:**
+  - Umbrella: [#655](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/655) — governed MCP restart coordination and zero-disruption recovery
+  - Vision: [#652](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/652) — MCP Control Plane Web Console product vision (§A system health and process control)
+  - Roadmap: [#653](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/653) — Control Plane Web Console phased delivery (Phase 2 restart controls)
+  - Contamination guard: [#630](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/630) — blocks manual process-kill recovery
+  - Console restart UX: [#642](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/642) — sanctioned restart and graceful reload
+  - Existing restart / reconnect paths to inventory: [#591](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/591) — auto-restart on master advance (closed); [#584](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/584) — host auto-reconnect on transport flap
+  - Stable-control runtime split: `docs/architecture/mcp-stable-control-runtime-policy-adr.md` (#615)
+  - Client-namespace health: `docs/mcp-namespace-health.md` (#543)
+  - Reconnect-only EOF recovery: `docs/mcp-namespace-eof-recovery.md`
+
+## 1. Context
+
+The Gitea MCP server is the **control plane** for real issue and PR mutations
+(create, comment, lock, review, merge, reconcile). The same process serves every
+role namespace (`gitea-author`, `gitea-reviewer`, `gitea-merger`,
+`gitea-reconciler`, `gitea-controller`) and holds the in-memory capability-gate
+code loaded at startup.
+
+Restarting that process is destructive to concurrent work:
+
+- It resets every session's identity, preflight, and capability-lease binding.
+- It can interrupt a mutation mid-critical-section (a lock acquire, a review
+  submit, a merge), leaving durable state half-written.
+- Relaunching from the wrong checkout or worktree silently changes which code
+  the control plane runs, defeating master-parity gates (#420 / #615).
+
+Today there is **no durable written policy** stating who may restart MCP, under
+what conditions, that restart is a last resort, and how controller approval,
+automated safety gates, and break-glass interact. Operators and LLM sessions
+therefore invent restart behavior ad hoc, which makes concurrent multi-role work
+unsafe. #630 and #642 need this policy as their backbone.
+
+This ADR defines that policy. It does **not** implement coordinator code or HA
+multi-instance restart (those are later children of #655).
+
+## 2. Decision
+
+### 2.1 v1 decision (recorded)
+
+**Restart authority in v1 is `controller approval + automated safety gates`.**
+
+A restart of the stable control runtime is authorized only when **both** hold:
+
+1. A **controller** role explicitly approves the restart, recording an audit
+   entry (who, why, scope, affected sessions), **and**
+2. The **automated safety gates** pass: a completed drain acknowledgement (no
+   affected session is mid-critical-section) or a declared break-glass incident
+   (§2.5).
+
+Quorum among multiple controllers is **not** required day-one. It is deferred
+unless a later investigation (tracked under #653) proves single-controller
+approval is insufficient. This ADR records the v1 decision so enforcement code
+(#630) has a fixed target; changing it requires a superseding ADR.
+
+### 2.2 Restart is a last resort — the recovery ladder
+
+Restart is the **last** rung. Before any restart, exhaust the narrower
+recoveries, in order:
+
+1. **Reconnect** the IDE/client MCP namespace (transport EOF, `client is
+   closing: EOF`, transient `#584` flap). No process change. See
+   `docs/mcp-namespace-eof-recovery.md`.
+2. **Refresh / rebind** the session workspace: re-run `gitea_whoami`,
+   `gitea_resolve_task_capability`, and pass an explicit validated
+   `worktree_path`. Fixes stale session context without touching the process.
+3. **Scoped restart** of a single misbehaving namespace/service (where the
+   deployment supports per-service restart) rather than the whole control plane.
+4. **Full restart** of the stable control runtime process — operator-owned,
+   controller-approved, drained.
+5. **Host / infrastructure restart** — the broadest action; same authorization
+   as a full restart plus infrastructure ownership.
+
+A session **must** try rungs 1–2 and record why they were insufficient before
+requesting a restart at rung 3 or above. Skipping straight to restart is a
+policy violation.
+
+### 2.3 Authorization matrix
+
+| Role | Reconnect (1) | Refresh/rebind (2) | Scoped restart (3) | Full restart (4) | Host restart (5) |
+|---|---|---|---|---|---|
+| **author** | self | self | request only | **forbidden** | forbidden |
+| **reviewer** | self | self | request only | **forbidden** | forbidden |
+| **merger** | self | self | request only | **forbidden** | forbidden |
+| **reconciler** | self | self | request only | **forbidden** | forbidden |
+| **controller** | self | self | **approve** (+gates) | **approve** (+gates) | request to operator |
+| **operator** | self | self | execute (controller-approved) | execute (controller-approved) | execute (controller-approved) |
+| **admin** | self | self | execute | execute | execute (break-glass) |
+
+Legend: *self* = may perform for its own client session; *request only* = may
+raise a restart request but not authorize or execute it; *approve* = may
+authorize under §2.1 gates; *execute* = may perform the process action after the
+authorization is recorded.
+
+Key invariants:
+
+- **No LLM worker role (author/reviewer/merger/reconciler) may perform or
+  authorize a full or host restart.** They may only reconnect/rebind their own
+  client and file a restart request.
+- **Controller approval authorizes; operator/admin executes.** The approving
+  controller and the executing operator may be the same human, but both the
+  approval and the execution are audited.
+- Privileged process actions (full restart, host restart) are reserved to
+  **operator/admin**, never to an automated worker.
+
+### 2.4 Approved conditions
+
+A restart at rung 3+ is approved only under one of these recorded conditions:
+
+- **No affected sessions:** the control plane has no live session that would be
+  interrupted (verified, not assumed).
+- **Full drain acknowledged:** every affected session has drained
+  (no open critical section — no held mutation lease mid-write) and the drain is
+  acknowledged in the audit record.
+- **Controller + gates:** controller approval plus passing automated safety
+  gates (§2.1), the standard v1 path.
+- **Quorum:** not required in v1; reserved for a future superseding ADR.
+- **Break-glass:** an incident-backed emergency exception (§2.5).
+
+Restart **never** bypasses mutation gates mid-critical-section. Drain before
+restart is mandatory except under break-glass with a declared incident.
+
+### 2.5 Break-glass
+
+Break-glass is a **separate, narrower** authorization path for emergencies where
+the normal drain-and-approve path cannot complete (e.g. the control plane is
+wedged and cannot drain).
+
+Break-glass conditions:
+
+- A declared incident record exists (id, timestamp, declarer) **before** the
+  action.
+- The action is taken by **operator or admin** authority only — never by an LLM
+  worker role, and never unilaterally by an operator with active peers when a
+  controller is reachable.
+- The scope is the minimum necessary rung of the ladder.
+- A **mandatory post-hoc audit** entry is filed: what was restarted, why the
+  normal path was impossible, which sessions were affected, and the incident id.
+
+Break-glass suspends the drain requirement, not the audit requirement.
+
+### 2.6 Explicit prohibitions
+
+- **A unilateral LLM or operator full restart while active peer sessions
+  exist is forbidden.** An LLM worker role must not kill, restart, or relaunch
+  the MCP process; a lone operator must not full-restart over live peer work
+  without controller approval or a break-glass incident.
+- Process-kill recovery is forbidden as a routine tool (#630). This ADR does not
+  introduce a kill path.
+- Ambiguous policy state **denies** restart (§4).
+
+## 3. Security requirements
+
+- Full restart and host restart are **privileged**; only operator/admin execute
+  them, only after a controller approval or break-glass incident is recorded.
+- Break-glass is a distinct authorization path with its own audit mandate; it is
+  never the default and never silent.
+- **Every approval and every restart action is audited** (who approved, who
+  executed, scope, affected sessions, condition, policy version). No restart is
+  authorized without a durable audit entry.
+
+## 4. Failure behavior
+
+**Ambiguous policy → deny restart.** If it cannot be established that a
+restart is authorized under §2 — unknown affected-session state, missing
+controller approval, absent break-glass incident, or an unclassifiable request —
+the safe action is to **refuse** the restart and stop with a recovery report,
+never to restart on assumption.
+
+## 5. Policy IDs (for enforcement code)
+
+Enforcement code — the restart coordinator (a later child of #655), the #630
+contamination guard, and the #642 console restart UX — binds to these stable
+policy identifiers rather than to prose:
+
+| Policy ID | Statement |
+|---|---|
+| `RG-01` | Restart is last resort; rungs 1–2 must be tried and recorded first (§2.2). |
+| `RG-02` | v1 authority = controller approval + automated safety gates (§2.1). |
+| `RG-03` | No LLM worker role performs or authorizes full/host restart (§2.3). |
+| `RG-04` | Full/host restart executed by operator/admin only, post approval (§2.3). |
+| `RG-05` | Drain before restart is mandatory except break-glass with incident (§2.4). |
+| `RG-06` | Break-glass requires a pre-declared incident and post-hoc audit (§2.5). |
+| `RG-07` | Unilateral LLM/operator full restart with active peers is forbidden (§2.6). |
+| `RG-08` | Ambiguous policy state denies restart (§4). |
+
+The `restart-governance/v1` **policy version** field is emitted on future
+restart audit events so approvals can be reconciled against the policy revision
+in force.
+
+## 6. Dogfooding
+
+Gitea-Tools governs its own MCP control plane by this policy. Author, reviewer,
+merger, and reconciler sessions operating on this repository use the recovery
+ladder (§2.2) — reconnect and rebind, never self-restart — and any real restart
+of the Gitea-Tools stable control runtime follows the controller-approval +
+drain path defined here.
+
+## 7. Acceptance and cross-links
+
+This ADR is the authoritative restart-governance policy. It **must** stay
+cross-linked from the safety model and the web-console deployment boundary:
+
+- `docs/safety-model.md` § Process restart governance references this ADR.
+- `docs/webui-deployment.md` references this ADR for restart/reload disposition.
+
+It is linked to its issue lineage — umbrella **#655**, vision **#652**, roadmap
+**#653**, contamination guard **#630**, and console restart UX **#642** — in
+§ Related above.
+
+## 8. Non-goals
+
+- Implementing the restart coordinator or approval state machine (#630, later
+  children of #655).
+- Implementing HA multi-instance restart or quorum machinery.
+- Introducing any process-kill or auto-restart tool; existing auto-restart
+  behavior must be inventoried before any new restart tool is enabled.

docs/mcp-restart-coordinator.md

@@ -0,0 +1,95 @@
+# MCP restart coordinator and impact analysis (#658)
+
+Before any sanctioned MCP restart, a central coordinator evaluates the live
+control-plane state and produces an **impact preview** so operators and the web
+console (#642 / #652) can see the blast radius *before* concurrent LLM work is
+disrupted. Uncoordinated restarts destroy in-flight author/reviewer/merger work
+and give operators no way to see what they are about to break.
+
+This lands the coordinator + impact DTO + a dry-run MCP tool. It is the single
+sanctioned entry point for restart evaluation post-#657 (which inventoried the
+restart/reload/kill paths). The **mutative apply** path — actually performing a
+restart — is a later child gated by a drain proof and is explicitly out of
+scope here.
+
+## Components
+
+| Piece | Where | Responsibility |
+|-------|-------|----------------|
+| `restart_coordinator.evaluate_restart_impact` | `restart_coordinator.py` | Pure classification: inventory → impact report DTO. No I/O, no restart. |
+| `RestartImpactReport` / `SessionImpact` / `LeaseImpact` | `restart_coordinator.py` | Console-facing DTO (`.as_dict()` is JSON-serializable). |
+| `ControlPlaneDB.list_sessions` | `control_plane_db.py` | Read-only session inventory (the process-level unit a restart kills). |
+| `gitea_request_mcp_restart` | `gitea_mcp_server.py` | MCP tool: gathers inventory from the #613 DB, calls the coordinator, returns the report. Dry-run only. |
+
+## Dimensions evaluated
+
+The coordinator classifies the inventory across the dimensions #658 requires:
+
+- **Sessions** — every active MCP session; a restart terminates all of them.
+  Liveness = `status == active` **and** the owner pid is alive **and** the
+  heartbeat is fresh (default window 15 min). Dead/stale sessions do not count
+  toward blast radius.
+- **Leases / locks** — control-plane leases joined with work items and their
+  freshness (`lease_lifecycle.classify_lease_freshness`). Only `active` (live
+  owner) leases are *disruptive*; expired / released / dead-process leases never
+  withhold a restart.
+- **Issue / PR work** — the issues and PRs behind disruptive leases.
+- **Mutations / critical sections** — a live lease carrying an author worktree
+  or a mutating phase (`implementing`, `publishing`, `merging`, …) is a
+  critical section a restart must not sever.
+- **Terminal (merge) lock** — an active terminal lock always makes a restart
+  unsafe.
+- **Prior recovery attempts** — narrower recovery already tried (e.g. sanctioned
+  client reconnects) is echoed so the operator sees the escalation history.
+
+## Verdict
+
+Exactly three verdicts, matching the acceptance criteria:
+
+| Verdict | `allow_restart` | Meaning |
+|---------|-----------------|---------|
+| `safe` | `true` | No other live sessions, no live leases, no terminal lock. |
+| `unsafe` | `false` | Live work would be disrupted and no operator override is present — **or** the inventory could not be completed (fail closed). |
+| `override` | `true` | Live work present, but an operator override accepts the blast radius. |
+
+`override_would_allow` tells the console whether an override path exists for the
+current state. `blast_radius` is a `none` / `low` / `medium` / `high` severity
+band derived from the affected session and work counts.
+
+### Fail closed
+
+If the control-plane inventory cannot be completed (DB unavailable, a listing
+failed), `inventory_complete` is `false` and the verdict is `unsafe` / deny. An
+incomplete evaluation must never green-light a restart.
+
+### Operator override authority
+
+Override authority is read from the environment variable
+`GITEA_OPERATOR_RESTART_OVERRIDE_AUTHORIZATION` and **never** from a tool
+argument. A worker session cannot set an environment variable on an
+already-running daemon, so override cannot be self-asserted (same pattern as the
+#630 daemon-maintenance authorization). The `request_override` tool argument only
+expresses caller intent; it takes effect solely when the environment
+authorization is present.
+
+## The tool
+
+```text
+gitea_request_mcp_restart(remote, host, org, repo,
+                          dry_run=True, request_override=False,
+                          session_id=None, limit=200)
+```
+
+Read-only, dry-run, and it **never restarts anything**. `apply_supported` is
+always `false`; passing `dry_run=False` performs no restart and reports that
+apply is gated by a drain proof (a separate child).
+
+## Audit
+
+Every evaluation carries an `audit_record` (event, coordinator version, verdict,
+allow decision, blast radius, counts, timestamp) so restart decisions are
+auditable. No secrets flow through the coordinator — session ids, pids, and
+profiles are operational metadata only.
+
+A representative dry-run report is in
+[`mcp-restart-impact-sample.json`](./mcp-restart-impact-sample.json).

docs/mcp-restart-impact-sample.json

@@ -0,0 +1,148 @@
+{
+  "coordinator_version": "1.0.0-issue-658",
+  "evaluated_at": "2026-07-24T06:00:00+00:00",
+  "dry_run": true,
+  "restart_performed": false,
+  "inventory_complete": true,
+  "incomplete_reasons": [],
+  "verdict": "unsafe",
+  "allow_restart": false,
+  "override_would_allow": true,
+  "operator_override": false,
+  "blast_radius": "high",
+  "reasons": [
+    "live work would be disrupted; restart denied without operator override",
+    "1 critical section(s) in flight (active lease with a live owner)"
+  ],
+  "affected_sessions": [
+    {
+      "session_id": "prgs-author-30988-d6f43c25",
+      "role": "author",
+      "profile": "prgs-author",
+      "pid": 1,
+      "status": "active",
+      "alive": true,
+      "heartbeat_stale": false,
+      "is_requester": false,
+      "live": true
+    },
+    {
+      "session_id": "prgs-reviewer-4157-0ce9",
+      "role": "reviewer",
+      "profile": "prgs-reviewer",
+      "pid": 1,
+      "status": "active",
+      "alive": true,
+      "heartbeat_stale": false,
+      "is_requester": true,
+      "live": true
+    }
+  ],
+  "affected_leases": [
+    {
+      "lease_id": "lease-abc",
+      "session_id": "prgs-author-30988-d6f43c25",
+      "role": "author",
+      "phase": "implementing",
+      "freshness": "active",
+      "work_kind": "issue",
+      "work_number": 658,
+      "worktree_path": "/repo/branches/feat-issue-658",
+      "disruptive": true,
+      "is_mutation": true,
+      "is_critical_section": true
+    },
+    {
+      "lease_id": "lease-dead",
+      "session_id": "prgs-author-91485",
+      "role": "author",
+      "phase": "allocated",
+      "freshness": "stale_dead_process",
+      "work_kind": "issue",
+      "work_number": 651,
+      "worktree_path": null,
+      "disruptive": false,
+      "is_mutation": false,
+      "is_critical_section": false
+    }
+  ],
+  "critical_sections": [
+    {
+      "lease_id": "lease-abc",
+      "session_id": "prgs-author-30988-d6f43c25",
+      "role": "author",
+      "phase": "implementing",
+      "freshness": "active",
+      "work_kind": "issue",
+      "work_number": 658,
+      "worktree_path": "/repo/branches/feat-issue-658",
+      "disruptive": true,
+      "is_mutation": true,
+      "is_critical_section": true
+    }
+  ],
+  "affected_issues": [
+    658
+  ],
+  "affected_prs": [],
+  "mutations": [
+    {
+      "lease_id": "lease-abc",
+      "session_id": "prgs-author-30988-d6f43c25",
+      "role": "author",
+      "phase": "implementing",
+      "freshness": "active",
+      "work_kind": "issue",
+      "work_number": 658,
+      "worktree_path": "/repo/branches/feat-issue-658",
+      "disruptive": true,
+      "is_mutation": true,
+      "is_critical_section": true
+    }
+  ],
+  "terminal_lock": null,
+  "ack_state": {
+    "prgs-author-30988-d6f43c25": "pending"
+  },
+  "prior_recovery_attempts": [
+    {
+      "kind": "client_reconnect",
+      "at": "2026-07-24T06:00:00+00:00",
+      "outcome": "insufficient"
+    }
+  ],
+  "counts": {
+    "sessions_total": 2,
+    "sessions_live_other": 1,
+    "leases_total": 2,
+    "leases_disruptive": 1,
+    "critical_sections": 1,
+    "mutations": 1,
+    "affected_issues": 1,
+    "affected_prs": 0,
+    "prior_recovery_attempts": 1
+  },
+  "audit_record": {
+    "event": "restart_impact_evaluated",
+    "coordinator_version": "1.0.0-issue-658",
+    "evaluated_at": "2026-07-24T06:00:00+00:00",
+    "dry_run": true,
+    "operator_override": false,
+    "requesting_session_id": "prgs-reviewer-4157-0ce9",
+    "inventory_complete": true,
+    "verdict": "unsafe",
+    "allow_restart": false,
+    "blast_radius": "high",
+    "counts": {
+      "sessions_total": 2,
+      "sessions_live_other": 1,
+      "leases_total": 2,
+      "leases_disruptive": 1,
+      "critical_sections": 1,
+      "mutations": 1,
+      "affected_issues": 1,
+      "affected_prs": 0,
+      "prior_recovery_attempts": 1
+    }
+  }
+}

docs/mcp-restart-path-inventory.md

@@ -0,0 +1,90 @@
+# MCP restart / reload / kill path inventory (#657)
+
+Complete inventory of every code, script, and host path that can **restart,
+reload, reconnect, kill, or force-recreate** an MCP process in this project,
+with each path classified and linked to the guard that constrains it.
+
+This document is the human-readable companion to the machine-readable registry
+in [`mcp_restart_paths.py`](../mcp_restart_paths.py). The two are kept in
+lock-step by [`tests/test_mcp_restart_paths.py`](../tests/test_mcp_restart_paths.py):
+every `path_id` below must appear in this file, and the source guards are run
+against the live tree.
+
+Roadmap linkage: this inventory is the enumeration step of the restart
+governance work — parent **#655**, restart-governance ADR **#656**, vision
+**#652**, roadmap **#653**. Related detection/guard work: master-advance
+staleness **#591**/**#420**, side-effect-free resolver **#685**, transport flap
+**#584**, manual-kill contamination **#630**.
+
+## Classifications
+
+| Classification | Meaning |
+|---|---|
+| `sanctioned_narrow_recovery` | One-shot, safe-by-construction recovery that never targets the running daemon. |
+| `guarded_fail_closed` | Detects a restart-requiring condition, then fails mutations closed and emits reconnect guidance. Never self-restarts. |
+| `forbidden` | A workflow-safety violation; where an LLM tool could invoke it, it is marked contamination. |
+| `removed` | A previously-existing unguarded restart primitive that has been deleted; a regression guard keeps it absent. |
+| `host_residual` | Behavior owned by the host/IDE, outside this process's control. Documented, not code-guarded here. |
+
+## The rule
+
+**No component may perform an unguarded full restart of the MCP daemon.** The
+in-process daemon (`gitea_mcp_server.py`, `mcp_server.py`,
+`role_session_router.py`) must never replace or terminate its own process:
+replacing the process after the host has wired up the stdio pipes desyncs the
+JSON-RPC transport (observed with Antigravity/Cascade hosts). Recovery is owned
+by the host/operator via a client reconnect — the daemon only ever *detects*
+and *fails closed*.
+
+## Inventory
+
+| path_id | Classification | Mechanism | Guard | Refs |
+|---|---|---|---|---|
+| `cli_venv_bootstrap_execv` | sanctioned_narrow_recovery | CLI wrapper scripts re-exec into `venv/bin/python3` via `os.execv`, guarded by `sys.executable != venv_python`. | One-shot pre-import bootstrap; runs before any MCP transport exists and only when not already on the venv interpreter; idempotent guard prevents a re-exec loop. | #657 |
+| `daemon_self_replacement` | forbidden | The daemon replacing/terminating its own process (`os.execv`/`os.kill`/`os._exit`) to reload code. | Forbidden by design; enforced against the source tree by `assert_no_daemon_self_replacement()`. | #657, #584 |
+| `legacy_auto_restart_helper` | removed | A helper (`_trigger_mcp_auto_restart`) that actively restarted the server from the read-only resolver path. | Removed in #685; kept absent by `assert_auto_restart_helper_absent()`. | #685, #657 |
+| `config_touch_reload` | removed | Touching (utime) the MCP client config to make the host reload the server. | Removed from the resolver in #685: stale detection is report-only, never mutating config, spawning threads, or calling `os._exit`. | #685, #657 |
+| `master_advance_auto_restart` | guarded_fail_closed | On-disk master advancing past the running code. | `master_parity_gate` captures startup parity and blocks mutations while stale, emitting restart guidance; the process never self-restarts. | #420, #591, #657 |
+| `stale_runtime_resolver_reconnect` | guarded_fail_closed | The capability resolver detecting a stale serving process. | Report-only (#685): returns `restart_required`/`stop_required` and an exact reconnect action; no restart, thread, config touch, or `os._exit`. | #685, #657 |
+| `manual_daemon_kill` | forbidden | Shell kills of the daemon: `pkill -f mcp_server.py`, `killall`, broad `pkill -f python` sweeps, or `kill <pid>` of a daemon pid. | Forbidden (#630): `runtime_recovery_guard` classifies these as contamination and `gitea_record_daemon_process_kill_attempt` writes a durable marker that fails later mutations closed. Operator maintenance authorization is read only from the environment. | #630, #657 |
+| `conflict_marker_infra_stop` | guarded_fail_closed | The daemon entrypoint scans for unresolved merge-conflict markers at startup and stops (`sys.exit(1)`). | Fail-closed startup stop, not a restart: the process exits and waits for the operator to resolve conflicts and relaunch; never loops. | #657 |
+| `ide_client_reconnect` | host_residual | A manual `/mcp reconnect` (or equivalent host action) that recreates the MCP client connection. | Outside this process's control; the sanctioned recovery the gates point operators toward. No in-process code initiates it. | #584, #656, #657 |
+| `profile_switch_runtime` | sanctioned_narrow_recovery | Switching the active execution profile at runtime (dynamic-profile mode). | In-process and restart-free: `runtime_switching_supported` is true, so a switch rebinds capability without recreating the process. | #656, #657 |
+
+## Guards enforced in CI
+
+`tests/test_mcp_restart_paths.py` asserts, against the live source tree:
+
+1. **Registry well-formedness** — every path has a valid classification, a
+   non-empty guard description, references, and locations; ids are unique; all
+   five classifications are represented.
+2. **Unknown restart attempts fail closed** —
+   `assert_restart_attempt_registered()` raises `UnknownRestartPathError` for
+   any path id not in this inventory, so a novel/unnamed restart primitive
+   cannot slip through silently.
+3. **Daemon never self-replaces** — `assert_no_daemon_self_replacement()` scans
+   the daemon modules for `os.execv`/`os.kill`/`os._exit`/`os.abort` calls
+   (comment/docstring mentions are ignored) and finds none.
+4. **Legacy helper stays removed** — `assert_auto_restart_helper_absent()`
+   confirms `_trigger_mcp_auto_restart` has not returned.
+5. **pkill stays forbidden** — a daemon `pkill` command still classifies as
+   contamination via `runtime_recovery_guard`.
+
+## Residual host behaviors (outside process control)
+
+* `/mcp reconnect` in the IDE/host — the sanctioned recovery for stale-runtime,
+  transport-flap (#584), and worktree-binding conditions. The daemon can only
+  emit guidance toward it.
+* Host-level process management (the operator relaunching the daemon after a
+  fail-closed stop, or after resolving merge conflicts).
+
+These are documented rather than code-guarded because the process cannot
+observe or gate them from inside itself.
+
+## Rollout
+
+Per #657, guards are introduced flag-free as **regression assertions** (they
+codify invariants that already hold) before any hard runtime block is layered
+on. When the restart coordinator (#655/#656) lands, registered paths gain a
+coordinator token/capability check; unregistered attempts already fail closed
+today via `assert_restart_attempt_registered()`.

docs/mcp-tool-inventory.md

@@ -136,6 +136,7 @@ that gates each call, not which tools exist.
 - `gitea_release_merger_pr_lease`
 - `gitea_release_reviewer_pr_lease`
 - `gitea_release_workflow_lease`
+- `gitea_request_mcp_restart`
 - `gitea_resolve_task_capability`
 - `gitea_resume_review_draft`
 - `gitea_review_pr`

docs/safety-model.md

@@ -46,3 +46,17 @@ If shell helpers are unavailable and MCP commit cannot run, stop with a recovery
 report (restart session, clear hung terminals, use MCP-native commit). See
 [`llm-workflow-runbooks.md`](llm-workflow-runbooks.md) § MCP-native commit path
 (#260) and agent temp artifact cleanup (#261).
+
+## 7. Process restart governance
+
+Restarting the MCP control-plane process is destructive to concurrent multi-role
+work and is governed by a dedicated policy. Restart is a **last resort** behind
+narrower recoveries (reconnect, rebind), full/host restart is reserved to
+operator/admin under **controller approval + automated safety gates**, a
+unilateral LLM or operator full restart with active peers is **forbidden**, and
+ambiguous policy state **denies** restart. Break-glass is a separate,
+incident-backed path with a mandatory audit.
+
+See [`architecture/mcp-restart-governance.md`](architecture/mcp-restart-governance.md)
+(#656) for the authorization matrix, the recovery ladder, break-glass
+conditions, and the `RG-01`–`RG-08` policy IDs.

docs/webui-deployment.md

@@ -55,6 +55,15 @@ shipped to the browser.
 assumption paths, and the client-secret policy. Use it to verify an instance is
 configured for internal-only operation.
 
+## Process restart / reload disposition
+
+The console never exposes a restart or reload control; process restart of the
+MCP control-plane runtime is governed separately. Restart is a last resort behind
+reconnect/rebind, full restart is operator/admin-only under controller approval
+plus safety gates, and break-glass is an incident-backed path. See
+[`architecture/mcp-restart-governance.md`](architecture/mcp-restart-governance.md)
+(#656).
+
 ## Non-goals (MVP)
 
 - Full SSO or session login in the UI

docs/webui-local-dev.md

@@ -54,6 +54,7 @@ status, onboarding checklist state, and the fail-closed error payloads (#635).
 | `/` | Home / operator overview |
 | `/health` | JSON liveness (`status`, `service`, `mode`, `timestamp`, `uptime_seconds`) |
 | `/api/v1/system/health` | Structured read-only system health (#634) |
+| `/system-health` | System-health dashboard — readiness, version/uptime, dependencies, MCP namespaces, stale-runtime parity (#639) |
 | `/queue` | Live PR and issue queue dashboard (#429) |
 | `/api/queue` | JSON queue export with pagination metadata |
 | `/projects` | Project registry list with status and onboarding progress (#427, #635) |
@@ -258,6 +259,37 @@ Not-yet-implemented surfaces (`/sessions`, `/inventory`, `/timeline`,
 surfaces are backed by #636). Mutating methods on stub routes still fail closed
 with `read-only-mvp`.
 
+## System-health dashboard (#639)
+
+`/system-health` renders the same snapshot the `/api/v1/system/health` API
+returns, so the page and the API can never disagree. Cards: overall readiness,
+stale-runtime parity, version and uptime, dependency probes, MCP namespaces,
+probe errors (only when present), and recovery pointers. `?deep=1` opts into
+the network probe exactly as the API does; the plain page load stays cheap.
+
+Field authority and honesty rules:
+
+* `ready` and `readiness_complete` are shown separately. A snapshot whose
+  required probes never ran is not the same as one that ran them and passed,
+  and the page never collapses the two into an unproven green.
+* A probe that did not run appears under **Not probed**, never as healthy.
+* `stale_runtime.mutation_safe` is displayed verbatim from the API. When the
+  runtime is stale, or when parity is indeterminate, the page warns and does
+  not claim mutation safety.
+* MCP namespaces are reported `unproven`: the web process runs outside the
+  IDE-managed MCP client and cannot prove that path (#543).
+
+Redaction is split by field kind. Free text — probe details, readiness and
+parity reasons, probe errors — passes through `system_health.redact`.
+Structured fields — commit SHAs, probe names, statuses, timestamps — are
+HTML-escaped only, because `redact`'s opaque-token rule matches any run of 32
+or more characters and would otherwise blank every 40-character git SHA, which
+is precisely the evidence the parity view exists to show.
+
+The dashboard is read-only: no restart, reload, or process-kill control. Those
+arrive in Phase 2 (#642). Recovery guidance points at the sanctioned client
+reconnect / operator restart path — never a manual daemon kill (#630).
+
 ## Deployment boundary (#435)
 
 MVP serves on loopback by default. Binding `0.0.0.0` or `::` is **refused**

issue_lock_provenance.py

@@ -16,11 +16,18 @@ ISSUE_LOCK_FILE = os.environ.get("GITEA_ISSUE_LOCK_FILE", "/tmp/gitea_issue_lock
 SOURCE_LOCK_ISSUE = "gitea_lock_issue"
 SOURCE_LOCK_ADOPTION = "gitea_lock_issue_adoption"
 SOURCE_OPERATOR_OVERRIDE = "operator_override"
+SOURCE_RECOVER_DIRTY_ORPHANED = "gitea_recover_dirty_orphaned_issue_worktree"
+# #864: dirty-preserving same-claimant author-session rebind (dead owner PID).
+SOURCE_DIRTY_SAME_CLAIMANT_REBIND = (
+    "gitea_rebind_dirty_same_claimant_author_session"
+)
 
 SANCTIONED_LOCK_SOURCES = frozenset({
     SOURCE_LOCK_ISSUE,
     SOURCE_LOCK_ADOPTION,
     SOURCE_OPERATOR_OVERRIDE,
+    SOURCE_RECOVER_DIRTY_ORPHANED,
+    SOURCE_DIRTY_SAME_CLAIMANT_REBIND,
 })
 
 _OPERATOR_OVERRIDE_ENV = "GITEA_ISSUE_LOCK_OPERATOR_OVERRIDE"

issue_lock_recovery.py

@@ -85,6 +85,12 @@ HEAD_RELATION_STRICT_DESCENDANT = "strict_descendant"
 # #772: an unpublished claim has no recorded head to compare against at all, so
 # its head is measured against the base the branch was cut from instead.
 HEAD_RELATION_DESCENDS_FROM_BASE = "descends_from_recorded_base"
+# #871: the remote/PR head advanced *past* the recorded head via a sanctioned
+# merge-based branch synchronization (``gitea_update_pr_branch_by_merge``) while
+# the local worktree stayed at the recorded head. This is the inverse of the
+# #768 descendant relation — here the *remote* strictly descends the local head,
+# and only because a base was merged into the branch, proven server-side.
+HEAD_RELATION_REMOTE_MERGE_SYNCED = "remote_merge_synced"
 
 # Which body of evidence a recovery was decided on (#772 AC10). These are not
 # interchangeable: a published claim proves ownership against a remote/PR head,
@@ -266,6 +272,70 @@ def _assess_base_descendancy(
     ]
 
 
+def _assess_remote_merge_synced(
+    sync_provenance: Mapping[str, Any] | None,
+    *,
+    recorded_head: str,
+    remote_head: str,
+) -> tuple[bool, list[str]]:
+    """Did ``remote_head`` advance past ``recorded_head`` via a sanctioned
+    merge-based branch sync (#871)?
+
+    ``sync_provenance`` is the server-side git observation from
+    ``issue_lock_worktree.read_merge_sync_provenance``. Its own
+    ``prior_head_sha`` / ``synced_head_sha`` are re-checked against the heads
+    this assessment is actually reasoning about, so an observation taken for some
+    other pair of commits — stale, mismatched, or hand-built — can never
+    authorize recovery. This is the inverse of ``_assess_strict_descendant``: the
+    recorded head is the ancestor and the *remote* head is the descendant, and it
+    is accepted only because the remote head is a base-into-branch merge that
+    preserved the branch mainline back to the recorded head.
+
+    Returns ``(proven, notes)``. Notes name the exact missing element so a
+    refused caller sees why, never a bare "unproven".
+    """
+    if not isinstance(sync_provenance, Mapping):
+        return False, [
+            "no server-derived merge-sync provenance observation was available; a "
+            "remote head ahead of the recorded head cannot be accepted"
+        ]
+
+    probe_prior = _text(sync_provenance.get("prior_head_sha"))
+    probe_synced = _text(sync_provenance.get("synced_head_sha"))
+    if probe_prior != recorded_head or probe_synced != remote_head:
+        return False, [
+            f"merge-sync observation covers {probe_prior or 'unknown'} -> "
+            f"{probe_synced or 'unknown'}, not the heads under assessment "
+            f"({recorded_head} -> {remote_head})"
+        ]
+    if not sync_provenance.get("probe_ok"):
+        return False, (
+            list(sync_provenance.get("reasons") or [])
+            or ["merge-sync provenance probe did not complete; provenance unproven"]
+        )
+    if not sync_provenance.get("prior_is_ancestor"):
+        return False, [
+            f"recorded head {recorded_head} is not an ancestor of remote head "
+            f"{remote_head}; a rewritten or force-moved head cannot be recovered"
+        ]
+    if not sync_provenance.get("is_merge_sync"):
+        return False, (
+            list(sync_provenance.get("reasons") or [])
+            or [
+                f"remote head {remote_head} is not a sanctioned merge-based sync "
+                f"of the base into the branch above {recorded_head}"
+            ]
+        )
+
+    proof = _text(sync_provenance.get("proof")) or (
+        f"{remote_head} merged the base into the branch above {recorded_head}"
+    )
+    return True, [
+        f"remote head {remote_head} advanced past recorded head {recorded_head} "
+        f"via a sanctioned merge-based branch sync ({proof})"
+    ]
+
+
 def assess_dead_session_lock_recovery(
     existing_lock: Mapping[str, Any] | None,
     *,
@@ -290,6 +360,7 @@ def assess_dead_session_lock_recovery(
     remote_branch_exists: bool | None = None,
     recorded_base_sha: str | None = None,
     base_ancestry: Mapping[str, Any] | None = None,
+    sync_provenance: Mapping[str, Any] | None = None,
 ) -> dict[str, Any]:
     """Decide whether a dead-session author lock may be natively recovered.
 
@@ -469,19 +540,39 @@ def assess_dead_session_lock_recovery(
                     head_relation = HEAD_RELATION_STRICT_DESCENDANT
                     ancestry_proof = notes[0] if notes else None
                 else:
-                    reasons.append(
+                    # #871: the reverse relation — the remote head advanced past
-                        f"local head {local_head} does not match remote branch head "
+                    # the recorded/local head via a sanctioned merge-based branch
-                        f"{remote_head}"
+                    # sync while the local worktree stayed put. Accepted only on
+                    # server-proven merge-sync provenance, never a caller claim.
+                    synced, sync_notes = _assess_remote_merge_synced(
+                        sync_provenance,
+                        recorded_head=local_head,
+                        remote_head=remote_head,
                     )
-                    reasons.extend(notes)
+                    if synced:
+                        head_relation = HEAD_RELATION_REMOTE_MERGE_SYNCED
+                        ancestry_proof = sync_notes[0] if sync_notes else None
+                    else:
+                        reasons.append(
+                            f"local head {local_head} does not match remote branch "
+                            f"head {remote_head}"
+                        )
+                        reasons.extend(notes)
+                        reasons.extend(sync_notes)
     evidence["recorded_base"] = recorded_base or None
     evidence["local_head"] = local_head or None
     evidence["remote_head"] = remote_head or None
     # ``recorded_head`` is the head recovery is being measured against;
     # ``accepted_head`` is the head this recovery actually adopts. They differ
     # only in the descendant case, and downstream gates need both (#768 AC2/AC7).
+    # #871: in the merge-sync case the branch/PR already carries the synced
+    # remote head, so that is the head recovery adopts; the local worktree stays
+    # at the ancestor recorded head.
     evidence["recorded_head"] = remote_head or None
-    evidence["accepted_head"] = local_head or None
+    if head_relation == HEAD_RELATION_REMOTE_MERGE_SYNCED:
+        evidence["accepted_head"] = remote_head or None
+    else:
+        evidence["accepted_head"] = local_head or None
     evidence["head_relation"] = head_relation
     evidence["ancestry_proof"] = ancestry_proof
 
@@ -493,12 +584,17 @@ def assess_dead_session_lock_recovery(
         # contradictory; re-stating it as a head mismatch would only obscure why.
         if not unpublished and local_head and pr_head != local_head:
             # A descendant recovery has not been published yet, so the open PR
-            # legitimately still points at the recorded head. Any other
+            # legitimately still points at the recorded head. A merge-sync
-            # disagreement is a real mismatch.
+            # recovery's PR legitimately sits at the advanced remote head. Any
+            # other disagreement is a real mismatch.
             if not (
                 head_relation == HEAD_RELATION_STRICT_DESCENDANT
                 and remote_head
                 and pr_head == remote_head
+            ) and not (
+                head_relation == HEAD_RELATION_REMOTE_MERGE_SYNCED
+                and remote_head
+                and pr_head == remote_head
             ):
                 reasons.append(
                     f"open PR #{pr_number} head {pr_head} does not match local head "
@@ -619,7 +715,11 @@ def assess_dead_session_lock_recovery(
         )
     if (
         head_relation
-        in (HEAD_RELATION_STRICT_DESCENDANT, HEAD_RELATION_DESCENDS_FROM_BASE)
+        in (
+            HEAD_RELATION_STRICT_DESCENDANT,
+            HEAD_RELATION_DESCENDS_FROM_BASE,
+            HEAD_RELATION_REMOTE_MERGE_SYNCED,
+        )
         and ancestry_proof
     ):
         proof.append(ancestry_proof)
@@ -697,6 +797,16 @@ def owning_pr_recovery_evidence(
             return None
         if accepted_head != local_head:
             return None
+    elif relation == HEAD_RELATION_REMOTE_MERGE_SYNCED:
+        # #871: the PR already sits at the advanced remote head; the local
+        # worktree is the ancestor the merge preserved. The head the open PR
+        # shows and the head recovery adopts are both the synced remote head.
+        if not remote_head or pr_head != remote_head:
+            return None
+        if accepted_head != remote_head:
+            return None
+        if not local_head or local_head == remote_head:
+            return None
     else:
         return None
     try:
@@ -765,6 +875,18 @@ def recovered_owning_pr_from_lock(
             return None
         if not accepted_head or accepted_head == recorded_head:
             return None
+    elif relation == HEAD_RELATION_REMOTE_MERGE_SYNCED:
+        # #871: PR sits at the advanced remote head, which is both the recorded
+        # measured-against head and the adopted head; the local worktree is the
+        # ancestor the merge preserved.
+        remote_head = _text(record.get("remote_head"))
+        local_head = _text(record.get("local_head"))
+        if not remote_head or pr_head != remote_head:
+            return None
+        if accepted_head and accepted_head != remote_head:
+            return None
+        if not local_head or local_head == remote_head:
+            return None
     else:
         return None
     try:

issue_lock_store.py

@@ -181,6 +181,7 @@ def bind_session_lock(
     *,
     expected_generation: int | None = None,
     renewal_sanctioned: bool = False,
+    recovery_sanctioned: bool = False,
 ) -> str:
     """Persist a keyed lock and bind it to the current process session.
 
@@ -225,7 +226,9 @@ def bind_session_lock(
     try:
         with _exclusive_file_lock(sentinel):
             existing = read_lock_file(path)
-            overwrite_block = assess_foreign_lock_overwrite(existing, record)
+            overwrite_block = assess_foreign_lock_overwrite(
+                existing, record, recovery_sanctioned=recovery_sanctioned
+            )
             if overwrite_block:
                 raise RuntimeError(overwrite_block)
             lease_block = assess_same_issue_lease_conflict(
@@ -234,6 +237,7 @@ def bind_session_lock(
                 branch_name=str(record.get("branch_name") or ""),
                 worktree_path=str(record.get("worktree_path") or ""),
                 renewal_sanctioned=renewal_sanctioned,
+                recovery_sanctioned=recovery_sanctioned,
             )
             if lease_block:
                 raise RuntimeError(lease_block)
@@ -814,8 +818,18 @@ def assess_lock_freshness(
     pid = lock_data.get("session_pid")
     if pid is None:
         pid = lock_data.get("pid")
-    # Evidence only. Never consulted to grant liveness (AC-N2).
+    if pid is None:
-    pid_alive = is_process_alive(pid) if pid is not None else False
+        pid = lock_data.get("owner_pid")
+    pid_missing = pid is None or str(pid).strip() == ""
+    try:
+        pid_int = int(pid) if not pid_missing else None
+        if pid_int is not None and pid_int <= 0:
+            pid_missing = True
+            pid_int = None
+    except (TypeError, ValueError):
+        pid_missing = True
+        pid_int = None
+    pid_alive = is_process_alive(pid_int) if pid_int is not None else False
 
     lifecycle = lease_lifecycle_version(lock_data)
     legacy = lifecycle != lease_policy.LIFECYCLE_HEARTBEAT_V1
@@ -823,6 +837,7 @@ def assess_lock_freshness(
 
     evidence: dict[str, Any] = {
         "pid_alive": pid_alive,
+        "pid_missing": pid_missing,
         "lifecycle": lifecycle,
         "legacy_lease": legacy,
         "task_session_id": lease_task_session_id(lock_data) or None,
@@ -1010,6 +1025,7 @@ def assess_same_issue_lease_conflict(
     worktree_path: str,
     operation_type: str = AUTHOR_ISSUE_WORK_LEASE,
     renewal_sanctioned: bool = False,
+    recovery_sanctioned: bool = False,
     now: datetime | None = None,
 ) -> str | None:
     """Return a fail-closed error when a competing live lease blocks acquisition.
@@ -1041,6 +1057,8 @@ def assess_same_issue_lease_conflict(
         existing_branch == branch_name
         and _same_realpath(str(existing_worktree or ""), worktree_path)
     )
+    if recovery_sanctioned and existing_issue == issue_number and existing_branch == branch_name:
+        return None
     expired = is_lease_expired(existing_lock, now=now)
     # #790 review #502/#516: a heartbeat-lifecycle lease that is non-live but
     # whose absolute expires_at is still in the future must enter the same
@@ -1094,10 +1112,26 @@ def assess_same_issue_lease_conflict(
     )
 
 
+def _lock_claimant(lock: dict[str, Any] | None) -> dict[str, str]:
+    if not isinstance(lock, dict):
+        return {}
+    claimant = lock.get("claimant")
+    if not isinstance(claimant, dict):
+        lease = lock.get("work_lease")
+        claimant = lease.get("claimant") if isinstance(lease, dict) else None
+    if not isinstance(claimant, dict):
+        return {}
+    return {
+        "username": str(claimant.get("username") or ""),
+        "profile": str(claimant.get("profile") or ""),
+    }
+
+
 def assess_foreign_lock_overwrite(
     existing_lock: dict[str, Any] | None,
     incoming_lock: dict[str, Any],
     *,
+    recovery_sanctioned: bool = False,
     now: datetime | None = None,
 ) -> str | None:
     """Block writes that would clobber an unrelated live lease on the same key."""
@@ -1112,8 +1146,31 @@ def assess_foreign_lock_overwrite(
     )
     if same_issue and same_branch and same_worktree:
         return None
-    if not is_lease_live(existing_lock, now=now):
+
+    existing_claimant = _lock_claimant(existing_lock)
+    incoming_claimant = _lock_claimant(incoming_lock)
+    same_claimant = (
+        bool(existing_claimant.get("username"))
+        and existing_claimant.get("username") == incoming_claimant.get("username")
+        and existing_claimant.get("profile") == incoming_claimant.get("profile")
+    )
+
+    if recovery_sanctioned and same_issue and same_branch and same_claimant:
         return None
+
+    if not is_lease_live(existing_lock, now=now):
+        # #860 F8: A non-live or PID-less lock still blocks foreign overwrite
+        # unless same claimant or sanctioned reclaim is proven.
+        if not same_claimant and same_issue:
+            reclaim = assess_expired_lock_reclaim(existing_lock, now=now)
+            if not reclaim.get("reclaim_allowed"):
+                return (
+                    "Refusing foreign overwrite of non-live issue lock "
+                    f"(issue #{existing_lock.get('issue_number')}, owner '{existing_claimant.get('username')}') "
+                    "without sanctioned reclaim proof (fail closed)"
+                )
+        return None
+
     return (
         "Refusing to overwrite a live foreign issue lock "
         f"(issue #{existing_lock.get('issue_number')}, "
@@ -1284,4 +1341,308 @@ def format_lock_proof(
         parts.append("lock released")
     elif released is False:
         parts.append("lock retained")
-    return "; ".join(parts)
+    return "; ".join(parts)
+
+
+# ── #871: durable linked-issue lock head refresh after branch synchronization ──
+_FULL_SHA_RE = re.compile(r"^[0-9a-f]{40}$", re.IGNORECASE)
+
+# Provenance recorded on the lock when the head is refreshed by a sanctioned
+# merge-based branch synchronization (``gitea_update_pr_branch_by_merge``).
+LOCK_HEAD_REFRESH_PROVENANCE_MERGE_SYNC = "gitea_update_pr_branch_by_merge"
+
+
+def _norm_sha(value: Any) -> str | None:
+    text = str(value or "").strip().lower()
+    return text if _FULL_SHA_RE.match(text) else None
+
+
+def _lock_claimant_view(lock: dict[str, Any] | None) -> dict[str, Any]:
+    if not isinstance(lock, dict):
+        return {}
+    claimant = lock.get("claimant")
+    if not isinstance(claimant, dict):
+        lease = lock.get("work_lease")
+        claimant = lease.get("claimant") if isinstance(lease, dict) else None
+    return dict(claimant) if isinstance(claimant, dict) else {}
+
+
+def assess_durable_lock_head_refresh(
+    existing_lock: dict[str, Any] | None,
+    *,
+    remote: str,
+    org: str,
+    repo: str,
+    issue_number: int,
+    branch_name: str,
+    worktree_path: str,
+    pr_number: int | None,
+    identity: str | None,
+    profile: str | None,
+    current_pid: int | None,
+    expected_old_head: str | None,
+    new_head: str | None,
+    base_head: str | None = None,
+) -> dict[str, Any]:
+    """Fail-closed assessment for refreshing a durable lock's recorded head (#871).
+
+    A successful ``gitea_update_pr_branch_by_merge`` advances the *remote* PR head
+    but must also advance the durable linked-issue lock so a later dead-session
+    recovery can prove ownership. This decides whether that refresh is permitted;
+    it mutates nothing.
+
+    Every element of durable ownership is re-verified against the persisted lock —
+    repository, issue, branch, worktree, claimant identity/profile, and the live
+    owning session — and the recorded head is compare-and-swapped: the lock's
+    currently recorded synced head (if any) must equal ``expected_old_head``, so a
+    lock whose head or provenance changed concurrently is never overwritten.
+    """
+    reasons: list[str] = []
+    old = _norm_sha(expected_old_head)
+    new = _norm_sha(new_head)
+    evidence: dict[str, Any] = {
+        "issue_number": issue_number,
+        "branch_name": branch_name,
+        "worktree_path": worktree_path,
+        "pr_number": pr_number,
+        "expected_old_head": old,
+        "new_head": new,
+        "base_head": _norm_sha(base_head),
+    }
+
+    if not isinstance(existing_lock, dict) or not existing_lock:
+        reasons.append("no durable lock exists for this issue; nothing to refresh")
+        return {"allowed": False, "reasons": reasons, "evidence": evidence,
+                "expected_generation": 0}
+
+    lock = dict(existing_lock)
+    evidence["current_generation"] = lock_generation(lock)
+
+    if lock.get("issue_number") != issue_number:
+        reasons.append(
+            f"durable lock targets issue #{lock.get('issue_number')}, not "
+            f"#{issue_number}; refusing head refresh"
+        )
+
+    for field, expected in (("remote", remote), ("org", org), ("repo", repo)):
+        actual = str(lock.get(field) or "").strip()
+        if actual != str(expected or "").strip():
+            reasons.append(
+                f"lock {field} '{actual}' does not match requested "
+                f"'{str(expected or '').strip()}'"
+            )
+
+    locked_branch = str(lock.get("branch_name") or "").strip()
+    if locked_branch != str(branch_name or "").strip():
+        reasons.append(
+            f"lock branch '{locked_branch}' does not match requested "
+            f"'{str(branch_name or '').strip()}'"
+        )
+
+    locked_worktree = str(lock.get("worktree_path") or "").strip()
+    try:
+        same_wt = bool(locked_worktree) and bool(worktree_path) and (
+            os.path.realpath(locked_worktree) == os.path.realpath(worktree_path)
+        )
+    except OSError:
+        same_wt = locked_worktree == (worktree_path or "")
+    if not same_wt:
+        reasons.append(
+            f"lock worktree '{locked_worktree}' does not match declared "
+            f"'{str(worktree_path or '').strip()}'"
+        )
+
+    claimant = _lock_claimant_view(lock)
+    locked_identity = str(claimant.get("username") or "").strip()
+    locked_profile = str(claimant.get("profile") or "").strip()
+    if not locked_identity or not locked_profile:
+        reasons.append(
+            "durable lock does not record a claimant identity/profile; "
+            "ownership could not be proven for head refresh"
+        )
+    if not str(identity or "").strip() or not str(profile or "").strip():
+        reasons.append(
+            "active session identity/profile is unknown; ownership could not be "
+            "proven for head refresh"
+        )
+    if locked_identity and str(identity or "").strip() and locked_identity != str(identity).strip():
+        reasons.append(
+            f"lock claimant '{locked_identity}' does not match active identity "
+            f"'{str(identity).strip()}'"
+        )
+    if locked_profile and str(profile or "").strip() and locked_profile != str(profile).strip():
+        reasons.append(
+            f"lock profile '{locked_profile}' does not match active profile "
+            f"'{str(profile).strip()}'"
+        )
+
+    # The refresh is written by the LIVE owning author session. A refresh is not
+    # a recovery: the current process must be the recorded owner.
+    recorded_pid = lock.get("session_pid")
+    if recorded_pid is None:
+        recorded_pid = lock.get("pid")
+    evidence["recorded_pid"] = recorded_pid
+    evidence["current_pid"] = current_pid
+    if current_pid is None:
+        reasons.append("current session pid is unknown; cannot prove live ownership")
+    else:
+        try:
+            if recorded_pid is None or int(recorded_pid) != int(current_pid):
+                reasons.append(
+                    f"durable lock is owned by pid {recorded_pid}, not the current "
+                    f"session pid {current_pid}; head refresh requires the live owner"
+                )
+        except (TypeError, ValueError):
+            reasons.append(
+                "durable lock owner pid is malformed; cannot prove live ownership"
+            )
+
+    if not old:
+        reasons.append("expected_old_head is not a full 40-char hex SHA (fail closed)")
+    if not new:
+        reasons.append("new_head is not a full 40-char hex SHA (fail closed)")
+    if old and new and old == new:
+        reasons.append(
+            "new head equals the expected old head; a sync must advance the head"
+        )
+
+    # Compare-and-swap on the recorded head: if the lock already records a synced
+    # head it must be exactly the expected old head, else another sync moved it.
+    recorded_synced = _norm_sha(lock.get("synced_pr_head"))
+    evidence["recorded_synced_pr_head"] = recorded_synced
+    if recorded_synced is not None and old is not None and recorded_synced != old:
+        reasons.append(
+            f"durable lock already records synced head {recorded_synced}, not the "
+            f"expected old head {old}; a concurrent sync changed it (CAS fail closed)"
+        )
+
+    if reasons:
+        return {"allowed": False, "reasons": reasons, "evidence": evidence,
+                "expected_generation": lock_generation(lock)}
+
+    return {
+        "allowed": True,
+        "reasons": [
+            f"durable lock for issue #{issue_number} branch '{locked_branch}' is "
+            f"owned by the live session; refresh recorded head {old} -> {new}"
+        ],
+        "evidence": evidence,
+        "expected_generation": lock_generation(lock),
+    }
+
+
+def apply_durable_lock_head_refresh(
+    *,
+    remote: str,
+    org: str,
+    repo: str,
+    issue_number: int,
+    branch_name: str,
+    worktree_path: str,
+    pr_number: int | None,
+    identity: str | None,
+    profile: str | None,
+    current_pid: int | None,
+    expected_old_head: str | None,
+    new_head: str | None,
+    synced_at: str,
+    base_head: str | None = None,
+    provenance: str = LOCK_HEAD_REFRESH_PROVENANCE_MERGE_SYNC,
+    lock_dir: str | None = None,
+) -> dict[str, Any]:
+    """CAS-refresh the durable lock's recorded head after a branch sync (#871).
+
+    Reads the durable lock from disk, re-asserts ownership via
+    ``assess_durable_lock_head_refresh``, and — only when permitted — writes the
+    new synced head through ``bind_session_lock`` with a generation compare-and-
+    swap. Then re-reads the lock and proves it records the complete new head
+    (read-after-write). Any failure at any step returns ``refreshed=False`` with
+    reasons; the caller must treat that as a partial lifecycle failure and never
+    report a fully successful synchronization.
+    """
+    existing = load_issue_lock(
+        remote=remote, org=org, repo=repo, issue_number=issue_number, lock_dir=lock_dir
+    )
+    assessment = assess_durable_lock_head_refresh(
+        existing,
+        remote=remote,
+        org=org,
+        repo=repo,
+        issue_number=issue_number,
+        branch_name=branch_name,
+        worktree_path=worktree_path,
+        pr_number=pr_number,
+        identity=identity,
+        profile=profile,
+        current_pid=current_pid,
+        expected_old_head=expected_old_head,
+        new_head=new_head,
+        base_head=base_head,
+    )
+    result: dict[str, Any] = {
+        "refreshed": False,
+        "read_after_write_ok": False,
+        "prior_head": _norm_sha(expected_old_head),
+        "new_head": _norm_sha(new_head),
+        "reasons": list(assessment.get("reasons") or []),
+        "evidence": assessment.get("evidence"),
+    }
+    if not assessment.get("allowed"):
+        return result
+
+    new = _norm_sha(new_head)
+    old = _norm_sha(expected_old_head)
+    record = dict(existing or {})
+    sync_block = {
+        "last_synced_pr_head": new,
+        "prior_pr_head": old,
+        "base_head": _norm_sha(base_head),
+        "pr_number": pr_number,
+        "provenance": provenance,
+        "synced_at": synced_at,
+        "synced_by_pid": current_pid,
+        "synced_by": {
+            "username": str(identity or "").strip() or None,
+            "profile": str(profile or "").strip() or None,
+        },
+    }
+    record["synced_pr_head"] = new
+    record["branch_sync"] = sync_block
+    history = record.get("branch_sync_history")
+    if not isinstance(history, list):
+        history = []
+    history = list(history)
+    history.append(sync_block)
+    record["branch_sync_history"] = history
+
+    try:
+        bind_session_lock(
+            record,
+            lock_dir=lock_dir,
+            expected_generation=assessment.get("expected_generation"),
+            renewal_sanctioned=True,
+        )
+    except Exception as exc:  # CAS miss or write failure — partial lifecycle failure
+        result["reasons"].append(
+            f"durable lock head refresh write failed (fail closed): {exc}"
+        )
+        return result
+
+    after = load_issue_lock(
+        remote=remote, org=org, repo=repo, issue_number=issue_number, lock_dir=lock_dir
+    )
+    after_head = _norm_sha((after or {}).get("synced_pr_head"))
+    result["lock_generation_after"] = lock_generation(after)
+    if after_head == new and new is not None:
+        result["refreshed"] = True
+        result["read_after_write_ok"] = True
+        result["reasons"].append(
+            f"durable lock recorded head refreshed to {new} and verified by "
+            "read-after-write"
+        )
+    else:
+        result["reasons"].append(
+            "read-after-write verification failed: durable lock does not record "
+            f"the new head {new} (found {after_head}); partial lifecycle failure"
+        )
+    return result

issue_lock_worktree.py

@@ -145,6 +145,175 @@ def read_head_ancestry(
     return result
 
 
+def read_merge_sync_provenance(
+    worktree_path: str,
+    *,
+    prior_head_sha: str | None,
+    synced_head_sha: str | None,
+) -> dict:
+    """Observe whether ``synced_head_sha`` is a sanctioned merge-based branch sync
+    that advanced the PR branch past ``prior_head_sha`` (#871).
+
+    ``gitea_update_pr_branch_by_merge`` advances a PR branch by merging the base
+    branch *into* the branch (``POST /pulls/{n}/update?style=merge``). The result
+    is a merge commit ``M`` on the branch whose **first** parent is the prior
+    branch head and whose second parent is the base tip. When the owning session
+    then dies without the durable lock's recorded head being refreshed, the local
+    worktree still sits at ``prior_head_sha`` while the live PR head is ``M``.
+
+    Recovering that drift safely requires proving the remote head is *exactly*
+    such a merge-sync — not a rewrite, rebase, force-push, or an unrelated
+    commit. This is that server-side observation. It reports facts only; the
+    disposition lives in ``issue_lock_recovery``. Every field is read from git in
+    the declared worktree — nothing is supplied by, or reachable from, an MCP
+    caller (#871).
+
+    Provenance is proven only when ALL hold:
+
+    * both commits are present (a rewritten/force-moved prior head leaves the
+      object graph and fails closed);
+    * ``prior_head_sha`` is a strict ancestor of ``synced_head_sha`` (the branch
+      history is preserved, never replaced);
+    * ``synced_head_sha`` is a merge commit (two or more parents), i.e. a base
+      merged in — a plain fast-forward of new direct commits is not a sync;
+    * ``prior_head_sha`` is an ancestor of the merge's **first** parent, so the
+      branch mainline (first-parent lineage) still reaches the prior head — a
+      rebase/force-push that re-authored the branch side fails this.
+    """
+    path = (worktree_path or "").strip()
+    prior = (prior_head_sha or "").strip()
+    synced = (synced_head_sha or "").strip()
+    result: dict = {
+        "prior_head_sha": prior or None,
+        "synced_head_sha": synced or None,
+        "probe_ok": False,
+        "prior_present": False,
+        "synced_present": False,
+        "prior_is_ancestor": False,
+        "synced_is_merge": False,
+        "first_parent_reaches_prior": False,
+        "is_merge_sync": False,
+        "first_parent_sha": None,
+        "parent_count": None,
+        "proof": None,
+        "reasons": [],
+    }
+    if not path or not prior or not synced:
+        result["reasons"].append(
+            "merge-sync provenance probe requires a worktree path and both "
+            "commit SHAs"
+        )
+        return result
+    if prior == synced:
+        result["reasons"].append(
+            "prior and synced heads are identical; no branch sync occurred"
+        )
+        return result
+
+    def _present(sha: str) -> bool:
+        res = subprocess.run(
+            ["git", "-C", path, "rev-parse", "--verify", "--quiet", f"{sha}^{{commit}}"],
+            capture_output=True,
+            text=True,
+            check=False,
+        )
+        return res.returncode == 0
+
+    def _is_ancestor(ancestor: str, descendant: str) -> bool | None:
+        res = subprocess.run(
+            ["git", "-C", path, "merge-base", "--is-ancestor", ancestor, descendant],
+            capture_output=True,
+            text=True,
+            check=False,
+        )
+        if res.returncode == 0:
+            return True
+        if res.returncode == 1:
+            return False
+        return None  # failed probe — never a silent "no"
+
+    try:
+        result["prior_present"] = _present(prior)
+        result["synced_present"] = _present(synced)
+    except OSError as exc:  # git unavailable — fail closed, never assume
+        result["reasons"].append(f"merge-sync provenance probe could not run: {exc}")
+        return result
+
+    if not result["prior_present"]:
+        result["reasons"].append(
+            f"prior head {prior} is not reachable in '{path}'; history may have "
+            "been rewritten or force-moved"
+        )
+    if not result["synced_present"]:
+        result["reasons"].append(
+            f"synced head {synced} is not reachable in '{path}'"
+        )
+    if not (result["prior_present"] and result["synced_present"]):
+        return result
+
+    ancestor = _is_ancestor(prior, synced)
+    if ancestor is None:
+        result["reasons"].append(
+            "ancestry probe failed; merge-sync provenance unproven"
+        )
+        return result
+    result["prior_is_ancestor"] = bool(ancestor)
+    if not ancestor:
+        result["reasons"].append(
+            f"prior head {prior} is not an ancestor of synced head {synced}; "
+            "the branch history was not preserved (not a merge-based sync)"
+        )
+        return result
+
+    parents_res = subprocess.run(
+        ["git", "-C", path, "rev-list", "--parents", "-n", "1", synced],
+        capture_output=True,
+        text=True,
+        check=False,
+    )
+    if parents_res.returncode != 0:
+        result["reasons"].append(
+            f"could not read parents of {synced}; merge-sync provenance unproven"
+        )
+        return result
+    tokens = (parents_res.stdout or "").split()
+    # tokens[0] is the commit itself; the rest are its parents.
+    parents = tokens[1:]
+    result["parent_count"] = len(parents)
+    result["synced_is_merge"] = len(parents) >= 2
+    if not result["synced_is_merge"]:
+        result["probe_ok"] = True
+        result["reasons"].append(
+            f"synced head {synced} has {len(parents)} parent(s); a merge-based "
+            "branch sync produces a merge commit (two or more parents)"
+        )
+        return result
+    first_parent = parents[0]
+    result["first_parent_sha"] = first_parent
+
+    fp_reaches = _is_ancestor(prior, first_parent) if prior != first_parent else True
+    if fp_reaches is None:
+        result["reasons"].append(
+            "first-parent ancestry probe failed; merge-sync provenance unproven"
+        )
+        return result
+    result["first_parent_reaches_prior"] = bool(fp_reaches)
+    result["probe_ok"] = True
+    if not fp_reaches:
+        result["reasons"].append(
+            f"merge first parent {first_parent} does not reach prior head "
+            f"{prior}; the branch mainline was re-authored (not a sanctioned sync)"
+        )
+        return result
+
+    result["is_merge_sync"] = True
+    result["proof"] = (
+        f"synced head {synced} is a merge commit (parents={len(parents)}) whose "
+        f"first-parent lineage reaches prior head {prior}; base merged into branch"
+    )
+    return result
+
+
 def read_recorded_base(
     worktree_path: str,
     *,

mcp_restart_paths.py

@@ -0,0 +1,475 @@
+"""Inventory and fail-closed guards for MCP restart/reload/kill paths (#657).
+
+Single source of truth enumerating every code/script/doc path that can
+restart, reload, reconnect, kill, or force-recreate an MCP process. Each path
+is classified and linked to the guard that constrains it. The companion
+human-readable inventory lives in ``docs/mcp-restart-path-inventory.md`` and is
+kept in lock-step with this module by ``tests/test_mcp_restart_paths.py``.
+
+Design intent (aligns with #655 restart-coordinator roadmap):
+
+* **No unguarded full restart.** The in-process MCP daemon
+  (``gitea_mcp_server.py`` / ``mcp_server.py`` / ``role_session_router.py``)
+  must never replace or kill its own process — replacing the process after the
+  host wired up the stdio pipes desyncs the JSON-RPC transport (observed with
+  Antigravity/Cascade hosts). ``assert_no_daemon_self_replacement`` enforces
+  this against the live source tree.
+* **No legacy auto-restart helper.** ``_trigger_mcp_auto_restart`` was removed
+  when the stale-runtime resolver became side-effect free (#685);
+  ``assert_auto_restart_helper_absent`` keeps it removed.
+* **Unknown restart attempts fail closed.** LLM tools must route any restart
+  intent through a *registered* path. ``assert_restart_attempt_registered``
+  raises ``UnknownRestartPathError`` for anything not in this inventory.
+* **pkill stays forbidden (#630).** Manual daemon kills are classified as
+  contamination by :mod:`runtime_recovery_guard`; this module records that path
+  and the test asserts the classification still holds.
+
+This module performs no restarts, spawns no threads, and touches no config or
+process state. It is pure inventory + read-only source assertions.
+"""
+
+from __future__ import annotations
+
+import os
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Iterable
+
+# --- Classifications -------------------------------------------------------
+
+#: A narrow, one-shot recovery that is safe by construction (e.g. a CLI wrapper
+#: re-execing into the venv interpreter before importing anything, or an
+#: in-process profile switch). Never targets the running MCP daemon process.
+CLASS_SANCTIONED_NARROW = "sanctioned_narrow_recovery"
+
+#: The path detects a condition that would require a restart, then *fails
+#: closed* on mutations and emits restart/reconnect guidance. It never restarts
+#: the process itself (recovery is owned by the host/operator).
+CLASS_GUARDED_FAIL_CLOSED = "guarded_fail_closed"
+
+#: The path is forbidden. Attempting it is a workflow-safety violation and,
+#: where an LLM tool could invoke it, is marked as contamination.
+CLASS_FORBIDDEN = "forbidden"
+
+#: A previously-existing unguarded restart primitive that has been deleted. A
+#: regression guard keeps it absent.
+CLASS_REMOVED = "removed"
+
+#: Behavior that lives in the host/IDE and is outside this process's control
+#: (e.g. a manual ``/mcp reconnect``). Documented, not code-guarded here.
+CLASS_HOST_RESIDUAL = "host_residual"
+
+VALID_CLASSIFICATIONS = frozenset(
+    {
+        CLASS_SANCTIONED_NARROW,
+        CLASS_GUARDED_FAIL_CLOSED,
+        CLASS_FORBIDDEN,
+        CLASS_REMOVED,
+        CLASS_HOST_RESIDUAL,
+    }
+)
+
+#: The in-process MCP daemon modules. These must never self-replace/self-kill.
+DAEMON_MODULES = (
+    "gitea_mcp_server.py",
+    "mcp_server.py",
+    "role_session_router.py",
+)
+
+#: The legacy auto-restart helper removed in #685. Must stay removed.
+LEGACY_AUTO_RESTART_HELPER = "_trigger_mcp_auto_restart"
+
+#: Call patterns that would let the daemon replace or terminate its own
+#: process. Matched as calls (trailing ``(``) so prose/docstring mentions such
+#: as "we do NOT os.execv() here" or "never calls ``os._exit``" do not trip the
+#: scanner (comment lines are stripped first regardless).
+DAEMON_SELF_REPLACEMENT_PRIMITIVES = (
+    "os.execv(",
+    "os.execve(",
+    "os.execvp(",
+    "os.execvpe(",
+    "os.kill(",
+    "os.killpg(",
+    "os._exit(",
+    "os.abort(",
+)
+
+
+@dataclass(frozen=True)
+class RestartPath:
+    """One classified restart/reload/kill path in the inventory."""
+
+    path_id: str
+    title: str
+    mechanism: str
+    classification: str
+    guard: str
+    locations: tuple[str, ...]
+    references: tuple[str, ...]
+    residual_host: bool = False
+    notes: str = ""
+
+
+class UnknownRestartPathError(RuntimeError):
+    """Raised when a restart attempt is not a registered, classified path."""
+
+
+# --- The inventory ---------------------------------------------------------
+
+_RESTART_PATHS: tuple[RestartPath, ...] = (
+    RestartPath(
+        path_id="cli_venv_bootstrap_execv",
+        title="CLI wrapper venv re-exec",
+        mechanism=(
+            "Standalone CLI scripts re-exec into venv/bin/python3 via os.execv "
+            "at import top, guarded by `sys.executable != venv_python`."
+        ),
+        classification=CLASS_SANCTIONED_NARROW,
+        guard=(
+            "One-shot, pre-import bootstrap; runs before any MCP transport "
+            "exists and only when not already on the venv interpreter, so it "
+            "cannot desync a live daemon. Idempotent guard condition prevents "
+            "a re-exec loop."
+        ),
+        locations=(
+            "create_pr.py",
+            "create_issue.py",
+            "close_issue.py",
+            "merge_pr.py",
+            "review_pr.py",
+            "edit_pr.py",
+            "delete_branch.py",
+            "mark_issue.py",
+            "manage_labels.py",
+            "list_issues.py",
+            "list_prs.py",
+        ),
+        references=("#657",),
+    ),
+    RestartPath(
+        path_id="daemon_self_replacement",
+        title="MCP daemon self-replacement",
+        mechanism=(
+            "The in-process MCP daemon replacing/terminating its own process "
+            "(os.execv/os.kill/os._exit) to reload code."
+        ),
+        classification=CLASS_FORBIDDEN,
+        guard=(
+            "Forbidden by design: replacing the process after the host wired "
+            "up stdio desyncs JSON-RPC (Antigravity/Cascade). Enforced against "
+            "the source tree by assert_no_daemon_self_replacement()."
+        ),
+        locations=("gitea_mcp_server.py:~155 (decision comment)",) + DAEMON_MODULES,
+        references=("#657", "#584"),
+    ),
+    RestartPath(
+        path_id="legacy_auto_restart_helper",
+        title="Legacy _trigger_mcp_auto_restart helper",
+        mechanism=(
+            "A helper that actively restarted the MCP server from the "
+            "read-only resolver path."
+        ),
+        classification=CLASS_REMOVED,
+        guard=(
+            "Removed in #685 when the resolver became side-effect free. Kept "
+            "absent by assert_auto_restart_helper_absent()."
+        ),
+        locations=("gitea_mcp_server.py", "mcp_server.py"),
+        references=("#685", "#657"),
+    ),
+    RestartPath(
+        path_id="config_touch_reload",
+        title="MCP client config-touch reload",
+        mechanism=(
+            "Touching (utime) the MCP client config file to make the host "
+            "reload/recreate the server process."
+        ),
+        classification=CLASS_REMOVED,
+        guard=(
+            "Removed from the resolver in #685: stale-runtime detection is "
+            "report-only and never mutates client config, spawns threads, or "
+            "calls os._exit."
+        ),
+        locations=("gitea_mcp_server.py (resolve_task_capability)",),
+        references=("#685", "#657"),
+    ),
+    RestartPath(
+        path_id="master_advance_auto_restart",
+        title="Master-advance staleness gate",
+        mechanism=(
+            "On-disk master advancing past the running code. The master-parity "
+            "gate detects it and fails mutations closed with restart guidance."
+        ),
+        classification=CLASS_GUARDED_FAIL_CLOSED,
+        guard=(
+            "Detect + fail closed only; the process never self-restarts. "
+            "master_parity_gate captures startup parity and blocks mutations "
+            "while stale, emitting restart/reconnect guidance."
+        ),
+        locations=(
+            "master_parity_gate.py",
+            "gitea_mcp_server.py (gitea_assess_master_parity)",
+        ),
+        references=("#420", "#591", "#657"),
+    ),
+    RestartPath(
+        path_id="stale_runtime_resolver_reconnect",
+        title="Stale-runtime resolver reconnect guidance",
+        mechanism=(
+            "The capability resolver detecting a stale serving process and "
+            "reporting restart_required/stop_required for a client reconnect."
+        ),
+        classification=CLASS_GUARDED_FAIL_CLOSED,
+        guard=(
+            "Report-only (#685): returns restart_required/stop_required and an "
+            "exact_safe_next_action pointing at IDE/client reconnect; performs "
+            "no restart, thread spawn, config touch, or os._exit."
+        ),
+        locations=("gitea_mcp_server.py (gitea_resolve_task_capability)",),
+        references=("#685", "#657"),
+    ),
+    RestartPath(
+        path_id="manual_daemon_kill",
+        title="Manual daemon kill (pkill/killall/kill)",
+        mechanism=(
+            "Shell kills of the MCP daemon: `pkill -f mcp_server.py`, "
+            "`killall`, broad `pkill -f python` sweeps, or `kill <pid>` of a "
+            "daemon pid."
+        ),
+        classification=CLASS_FORBIDDEN,
+        guard=(
+            "Forbidden (#630): runtime_recovery_guard classifies these as "
+            "contamination and gitea_record_daemon_process_kill_attempt writes "
+            "a durable marker that fails subsequent mutations closed. Operator "
+            "maintenance authorization is read only from the environment, not "
+            "from a tool argument."
+        ),
+        locations=(
+            "runtime_recovery_guard.py",
+            "gitea_mcp_server.py (gitea_record_daemon_process_kill_attempt)",
+        ),
+        references=("#630", "#657"),
+    ),
+    RestartPath(
+        path_id="conflict_marker_infra_stop",
+        title="Startup conflict-marker infra stop",
+        mechanism=(
+            "The daemon entrypoint scans for unresolved merge-conflict markers "
+            "at startup and stops (sys.exit(1)) if found."
+        ),
+        classification=CLASS_GUARDED_FAIL_CLOSED,
+        guard=(
+            "Fail-closed startup stop, not a restart: the process exits and "
+            "waits for the operator to resolve conflicts and relaunch. Never "
+            "self-restarts or loops."
+        ),
+        locations=("mcp_server.py (check_conflict_markers)",),
+        references=("#657",),
+    ),
+    RestartPath(
+        path_id="ide_client_reconnect",
+        title="Host/IDE MCP reconnect",
+        mechanism=(
+            "A manual `/mcp reconnect` (or equivalent host action) that the "
+            "IDE performs to recreate the MCP client connection."
+        ),
+        classification=CLASS_HOST_RESIDUAL,
+        guard=(
+            "Outside this process's control. It is the sanctioned recovery the "
+            "gates point operators toward; documented as residual host "
+            "behavior. No in-process code initiates it."
+        ),
+        locations=("host/IDE",),
+        references=("#584", "#656", "#657"),
+        residual_host=True,
+    ),
+    RestartPath(
+        path_id="profile_switch_runtime",
+        title="Runtime profile switch",
+        mechanism=(
+            "Switching the active execution profile at runtime "
+            "(dynamic-profile mode)."
+        ),
+        classification=CLASS_SANCTIONED_NARROW,
+        guard=(
+            "In-process and restart-free: runtime_switching_supported is true, "
+            "so a profile switch rebinds capability without recreating the "
+            "process. No restart primitive is invoked."
+        ),
+        locations=("gitea_mcp_server.py (gitea_activate_profile)",),
+        references=("#656", "#657"),
+    ),
+)
+
+_BY_ID: dict[str, RestartPath] = {p.path_id: p for p in _RESTART_PATHS}
+
+
+# --- Read-only accessors ---------------------------------------------------
+
+
+def iter_restart_paths() -> tuple[RestartPath, ...]:
+    """Return the full inventory as an immutable tuple."""
+
+    return _RESTART_PATHS
+
+
+def restart_path_ids() -> frozenset[str]:
+    """Return the set of registered path ids."""
+
+    return frozenset(_BY_ID)
+
+
+def get_restart_path(path_id: str) -> RestartPath:
+    """Return the registered path, or raise :class:`UnknownRestartPathError`."""
+
+    try:
+        return _BY_ID[path_id]
+    except KeyError as exc:
+        raise UnknownRestartPathError(
+            f"unknown restart path id {path_id!r}; not in the #657 inventory"
+        ) from exc
+
+
+def paths_by_classification(classification: str) -> tuple[RestartPath, ...]:
+    """Return all registered paths with the given classification."""
+
+    if classification not in VALID_CLASSIFICATIONS:
+        raise ValueError(f"unknown classification {classification!r}")
+    return tuple(p for p in _RESTART_PATHS if p.classification == classification)
+
+
+def assert_restart_attempt_registered(path_id: str) -> RestartPath:
+    """Fail closed unless ``path_id`` is a registered, classified restart path.
+
+    LLM tools that intend to trigger any restart/reload/reconnect must name a
+    registered path so an unknown/novel restart primitive cannot slip through
+    silently. Forbidden and removed paths are registered too — this only
+    asserts the attempt is *known*, not that it is *permitted*; callers must
+    still honor the classification.
+    """
+
+    return get_restart_path(path_id)
+
+
+def assert_registry_wellformed() -> None:
+    """Validate the inventory's own invariants (fail closed on drift)."""
+
+    seen: set[str] = set()
+    for path in _RESTART_PATHS:
+        if path.path_id in seen:
+            raise ValueError(f"duplicate restart path id {path.path_id!r}")
+        seen.add(path.path_id)
+        if path.classification not in VALID_CLASSIFICATIONS:
+            raise ValueError(
+                f"{path.path_id!r} has invalid classification "
+                f"{path.classification!r}"
+            )
+        if not path.guard.strip():
+            raise ValueError(f"{path.path_id!r} is missing a guard description")
+        if not path.references:
+            raise ValueError(f"{path.path_id!r} is missing references")
+        if not path.locations:
+            raise ValueError(f"{path.path_id!r} is missing locations")
+        if path.classification == CLASS_HOST_RESIDUAL and not path.residual_host:
+            raise ValueError(
+                f"{path.path_id!r} is host_residual but residual_host is False"
+            )
+
+
+# --- Source-tree guards ----------------------------------------------------
+
+
+def _repo_root(root: str | os.PathLike[str] | None = None) -> Path:
+    if root is not None:
+        return Path(root)
+    return Path(__file__).resolve().parent
+
+
+def _iter_code_lines(text: str) -> Iterable[tuple[int, str]]:
+    """Yield (1-based lineno, line) for lines that are not full-line comments."""
+
+    for lineno, line in enumerate(text.splitlines(), start=1):
+        if line.lstrip().startswith("#"):
+            continue
+        yield lineno, line
+
+
+def scan_daemon_self_replacement(
+    root: str | os.PathLike[str] | None = None,
+) -> list[dict[str, object]]:
+    """Return violations where a daemon module could self-replace/self-kill.
+
+    Scans :data:`DAEMON_MODULES` for calls in
+    :data:`DAEMON_SELF_REPLACEMENT_PRIMITIVES`. Full-line comments are ignored,
+    and only call forms (with a trailing ``(``) match, so decision comments and
+    docstrings that merely mention the primitives do not produce false hits.
+    """
+
+    repo = _repo_root(root)
+    violations: list[dict[str, object]] = []
+    for module in DAEMON_MODULES:
+        path = repo / module
+        if not path.exists():
+            continue
+        text = path.read_text(encoding="utf-8", errors="replace")
+        for lineno, line in _iter_code_lines(text):
+            for primitive in DAEMON_SELF_REPLACEMENT_PRIMITIVES:
+                if primitive in line:
+                    violations.append(
+                        {
+                            "module": module,
+                            "line": lineno,
+                            "primitive": primitive,
+                            "text": line.strip(),
+                        }
+                    )
+    return violations
+
+
+def assert_no_daemon_self_replacement(
+    root: str | os.PathLike[str] | None = None,
+) -> None:
+    """Fail closed if any daemon module can restart/kill its own process."""
+
+    violations = scan_daemon_self_replacement(root)
+    if violations:
+        rendered = "; ".join(
+            f"{v['module']}:{v['line']} {v['primitive']}" for v in violations
+        )
+        raise AssertionError(
+            "MCP daemon must never self-replace/self-kill (#657); found: "
+            f"{rendered}"
+        )
+
+
+def scan_auto_restart_helper(
+    root: str | os.PathLike[str] | None = None,
+) -> list[dict[str, object]]:
+    """Return occurrences of a *definition* of the legacy auto-restart helper."""
+
+    repo = _repo_root(root)
+    needle = f"def {LEGACY_AUTO_RESTART_HELPER}"
+    hits: list[dict[str, object]] = []
+    for module in DAEMON_MODULES:
+        path = repo / module
+        if not path.exists():
+            continue
+        text = path.read_text(encoding="utf-8", errors="replace")
+        for lineno, line in _iter_code_lines(text):
+            if needle in line:
+                hits.append({"module": module, "line": lineno})
+    return hits
+
+
+def assert_auto_restart_helper_absent(
+    root: str | os.PathLike[str] | None = None,
+) -> None:
+    """Fail closed if the removed ``_trigger_mcp_auto_restart`` reappears."""
+
+    hits = scan_auto_restart_helper(root)
+    if hits:
+        rendered = "; ".join(f"{h['module']}:{h['line']}" for h in hits)
+        raise AssertionError(
+            f"{LEGACY_AUTO_RESTART_HELPER} was removed in #685 and must not "
+            f"return (#657); found definition at: {rendered}"
+        )

pr_work_lease.py

@@ -228,25 +228,74 @@ def find_active_reviewer_lease(
     return None
 
 
+def _conflict_fix_chain_key(lease: dict) -> tuple | None:
+    """Identity of the lease chain a conflict-fix marker belongs to (#842).
+
+    Keyed by PR number, profile, head_before, and branch. Returns None when any
+    required component (pr_number, profile, head_before) is missing or malformed.
+    """
+    raw = lease.get("raw_fields") or {}
+    pr_number = lease.get("pr_number")
+    profile = (lease.get("profile") or "").strip().lower()
+    head_before = lease.get("head_before")
+    branch = (lease.get("branch") or raw.get("branch") or "").strip()
+    if not (pr_number and profile and head_before):
+        return None
+    return (pr_number, profile, head_before, branch)
+
+
+def _conflict_fix_chain_matches(key1: tuple, key2: tuple) -> bool:
+    """True when two conflict-fix chain keys refer to the same lease chain."""
+    pr1, profile1, head1, branch1 = key1
+    pr2, profile2, head2, branch2 = key2
+    if pr1 != pr2 or profile1 != profile2 or head1 != head2:
+        return False
+    if branch1 and branch2 and branch1 != branch2:
+        return False
+    return True
+
+
+def _conflict_fix_chain_terminated_after(entries: list[dict], index: int) -> bool:
+    """True when a later marker terminates the conflict-fix chain of ``entries[index]``.
+
+    Append-only newest-wins: a terminal marker (phase=released/blocked/done)
+    ends only its matching claim chain (#842).
+    """
+    key = _conflict_fix_chain_key(entries[index])
+    if key is None:
+        return False
+    for later in entries[index + 1:]:
+        phase = (later.get("phase") or "").strip().lower()
+        if phase not in _TERMINAL_CONFLICT_FIX_PHASES:
+            continue
+        later_key = _conflict_fix_chain_key(later)
+        if later_key and _conflict_fix_chain_matches(key, later_key):
+            return True
+    return False
+
+
 def find_active_conflict_fix_lease(
     comments: list[dict],
     *,
     pr_number: int,
     now: datetime | None = None,
 ) -> dict[str, Any] | None:
-    """Return the newest unexpired conflict-fix lease for *pr_number*, if any."""
+    """Return the newest unexpired, non-terminated conflict-fix lease for *pr_number*, if any."""
     now = now or datetime.now(timezone.utc)
     candidates = [
         entry for entry in _comment_entries(comments, pr_number=pr_number)
         if entry.get("lease_kind") == "conflict_fix"
     ]
-    for lease in reversed(candidates):
+    for index in range(len(candidates) - 1, -1, -1):
+        lease = candidates[index]
         if _lease_expired(lease, now=now):
             continue
         phase = (lease.get("phase") or "").strip().lower()
         if phase in _TERMINAL_CONFLICT_FIX_PHASES:
             continue
         if phase in _ACTIVE_CONFLICT_FIX_PHASES or phase:
+            if _conflict_fix_chain_terminated_after(candidates, index):
+                continue
             return lease
     return None
 

restart_coordinator.py

@@ -0,0 +1,451 @@
+"""MCP restart coordinator and impact analysis (#658).
+
+Before any sanctioned MCP restart, a central coordinator must evaluate the
+live control-plane state — active sessions, leases/locks, in-flight issue/PR
+work, mutations, worktrees, and recovery history — and produce an *impact
+preview* so operators (and the web console, #642/#652) can see the blast
+radius **before** concurrent LLM work is disrupted.
+
+Design rules (mirrors the read-only posture of ``workflow_dashboard`` /
+``lease_lifecycle``):
+
+* **Pure classification.** :func:`evaluate_restart_impact` takes an already
+  gathered inventory and returns a structured report. It never touches the
+  network, the filesystem, or a live process, so multi-session fixtures can
+  drive every branch in unit tests. The coordinator *never restarts anything*;
+  a mutative apply path is a later child gated by a drain proof (non-goal here).
+* **Fail closed.** If the inventory is not explicitly complete, the verdict is
+  ``unsafe`` / deny — an incomplete evaluation must never green-light a restart.
+* **No secrets.** Session ids, pids, and profiles are operational metadata, not
+  credentials; nothing secret flows through this module.
+
+The single sanctioned entry point post-#657 is the MCP tool
+``gitea_request_mcp_restart`` (dry-run by default), which gathers the inventory
+from the #613 control-plane DB and calls :func:`evaluate_restart_impact`.
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from datetime import datetime, timezone
+from typing import Any, Mapping, Sequence
+
+import lease_lifecycle
+
+COORDINATOR_VERSION = "1.0.0-issue-658"
+
+# Restart verdicts. Exactly the three the acceptance criteria name.
+VERDICT_SAFE = "safe"
+VERDICT_UNSAFE = "unsafe"
+VERDICT_OVERRIDE = "override"
+
+# Blast-radius severity bands.
+BLAST_NONE = "none"
+BLAST_LOW = "low"
+BLAST_MEDIUM = "medium"
+BLAST_HIGH = "high"
+
+# A live lease with a live owner process is treated as active in-flight work.
+LEASE_FRESHNESS_LIVE = "active"
+
+# Default staleness window for a session heartbeat (seconds). A session whose
+# last heartbeat is older than this is not counted as live even if its row is
+# still marked ``active`` — it is assumed dead/detached.
+DEFAULT_SESSION_HEARTBEAT_STALE_SECONDS = 900
+
+
+def _utc_now() -> datetime:
+    return datetime.now(timezone.utc)
+
+
+def _parse_ts(value: str | None) -> datetime | None:
+    return lease_lifecycle._parse_ts(value)
+
+
+@dataclass(frozen=True)
+class SessionImpact:
+    """One MCP session a restart would terminate."""
+
+    session_id: str
+    role: str | None
+    profile: str | None
+    pid: int | None
+    status: str | None
+    alive: bool | None
+    heartbeat_stale: bool
+    is_requester: bool
+    live: bool
+
+    def as_dict(self) -> dict[str, Any]:
+        return {
+            "session_id": self.session_id,
+            "role": self.role,
+            "profile": self.profile,
+            "pid": self.pid,
+            "status": self.status,
+            "alive": self.alive,
+            "heartbeat_stale": self.heartbeat_stale,
+            "is_requester": self.is_requester,
+            "live": self.live,
+        }
+
+
+@dataclass(frozen=True)
+class LeaseImpact:
+    """One control-plane lease a restart would disrupt."""
+
+    lease_id: str | None
+    session_id: str | None
+    role: str | None
+    phase: str | None
+    freshness: str | None
+    work_kind: str | None
+    work_number: int | None
+    worktree_path: str | None
+    disruptive: bool
+    is_mutation: bool
+    is_critical_section: bool
+
+    def as_dict(self) -> dict[str, Any]:
+        return {
+            "lease_id": self.lease_id,
+            "session_id": self.session_id,
+            "role": self.role,
+            "phase": self.phase,
+            "freshness": self.freshness,
+            "work_kind": self.work_kind,
+            "work_number": self.work_number,
+            "worktree_path": self.worktree_path,
+            "disruptive": self.disruptive,
+            "is_mutation": self.is_mutation,
+            "is_critical_section": self.is_critical_section,
+        }
+
+
+@dataclass(frozen=True)
+class RestartImpactReport:
+    """Impact preview DTO returned to the console / operator (#642/#652)."""
+
+    coordinator_version: str
+    evaluated_at: str
+    dry_run: bool
+    restart_performed: bool
+    inventory_complete: bool
+    verdict: str
+    allow_restart: bool
+    override_would_allow: bool
+    operator_override: bool
+    blast_radius: str
+    reasons: list[str]
+    affected_sessions: list[SessionImpact]
+    affected_leases: list[LeaseImpact]
+    critical_sections: list[LeaseImpact]
+    affected_issues: list[int]
+    affected_prs: list[int]
+    mutations: list[LeaseImpact]
+    terminal_lock: dict[str, Any] | None
+    ack_state: dict[str, str]
+    prior_recovery_attempts: list[dict[str, Any]]
+    counts: dict[str, int]
+    audit_record: dict[str, Any]
+    incomplete_reasons: list[str] = field(default_factory=list)
+
+    def as_dict(self) -> dict[str, Any]:
+        return {
+            "coordinator_version": self.coordinator_version,
+            "evaluated_at": self.evaluated_at,
+            "dry_run": self.dry_run,
+            "restart_performed": self.restart_performed,
+            "inventory_complete": self.inventory_complete,
+            "incomplete_reasons": list(self.incomplete_reasons),
+            "verdict": self.verdict,
+            "allow_restart": self.allow_restart,
+            "override_would_allow": self.override_would_allow,
+            "operator_override": self.operator_override,
+            "blast_radius": self.blast_radius,
+            "reasons": list(self.reasons),
+            "affected_sessions": [s.as_dict() for s in self.affected_sessions],
+            "affected_leases": [l.as_dict() for l in self.affected_leases],
+            "critical_sections": [l.as_dict() for l in self.critical_sections],
+            "affected_issues": list(self.affected_issues),
+            "affected_prs": list(self.affected_prs),
+            "mutations": [l.as_dict() for l in self.mutations],
+            "terminal_lock": self.terminal_lock,
+            "ack_state": dict(self.ack_state),
+            "prior_recovery_attempts": list(self.prior_recovery_attempts),
+            "counts": dict(self.counts),
+            "audit_record": dict(self.audit_record),
+        }
+
+
+def _classify_session(
+    row: Mapping[str, Any],
+    *,
+    now: datetime,
+    requesting_session_id: str | None,
+    heartbeat_stale_seconds: int,
+) -> SessionImpact:
+    session_id = str(row.get("session_id") or "")
+    pid = row.get("pid")
+    status = (row.get("status") or "").strip().lower() or None
+    alive = lease_lifecycle.is_process_alive(pid) if pid is not None else None
+    hb = _parse_ts(row.get("last_heartbeat_at"))
+    heartbeat_stale = bool(
+        hb is not None and (now - hb).total_seconds() > heartbeat_stale_seconds
+    )
+    live = bool(status == "active" and alive is not False and not heartbeat_stale)
+    return SessionImpact(
+        session_id=session_id,
+        role=row.get("role"),
+        profile=row.get("profile"),
+        pid=pid,
+        status=status,
+        alive=alive,
+        heartbeat_stale=heartbeat_stale,
+        is_requester=bool(
+            requesting_session_id and session_id == requesting_session_id
+        ),
+        live=live,
+    )
+
+
+# Lease phases that represent an active mutation in flight (as opposed to a
+# mere allocation/claim with no work committed yet). An active lease in any of
+# these phases is a critical section a restart must not sever.
+_MUTATING_PHASES = frozenset(
+    {
+        "implementing",
+        "publishing",
+        "pushing",
+        "committing",
+        "reviewing",
+        "merging",
+        "reconciling",
+        "conflict_fix",
+    }
+)
+
+
+def _classify_lease(row: Mapping[str, Any]) -> LeaseImpact:
+    freshness_obj = row.get("freshness")
+    if isinstance(freshness_obj, Mapping):
+        freshness = str(freshness_obj.get("freshness") or "").strip().lower() or None
+    else:
+        freshness = str(freshness_obj or "").strip().lower() or None
+    phase = (row.get("phase") or "").strip().lower() or None
+    worktree = row.get("worktree_path")
+    disruptive = freshness == LEASE_FRESHNESS_LIVE
+    # A live lease is a mutation-in-flight if it carries an author worktree or
+    # its phase names a mutating step. All disruptive leases are critical
+    # sections a restart would sever regardless.
+    is_mutation = bool(
+        disruptive and (bool(worktree) or (phase in _MUTATING_PHASES))
+    )
+    number = row.get("work_number")
+    try:
+        number = int(number) if number is not None else None
+    except (TypeError, ValueError):
+        number = None
+    return LeaseImpact(
+        lease_id=row.get("lease_id"),
+        session_id=row.get("session_id"),
+        role=row.get("role"),
+        phase=phase,
+        freshness=freshness,
+        work_kind=(str(row.get("work_kind") or "").strip().lower() or None),
+        work_number=number,
+        worktree_path=worktree,
+        disruptive=disruptive,
+        is_mutation=is_mutation,
+        is_critical_section=disruptive,
+    )
+
+
+def _blast_radius(*, session_count: int, work_count: int, mutation_count: int) -> str:
+    if mutation_count > 0 or work_count >= 3 or session_count >= 3:
+        return BLAST_HIGH
+    if work_count > 0 or session_count == 2:
+        return BLAST_MEDIUM
+    if session_count == 1:
+        return BLAST_LOW
+    return BLAST_NONE
+
+
+def evaluate_restart_impact(
+    inventory: Mapping[str, Any],
+    *,
+    now: datetime | None = None,
+    operator_override: bool = False,
+    requesting_session_id: str | None = None,
+    dry_run: bool = True,
+    session_heartbeat_stale_seconds: int = DEFAULT_SESSION_HEARTBEAT_STALE_SECONDS,
+) -> RestartImpactReport:
+    """Evaluate a proposed MCP restart and return an impact preview.
+
+    ``inventory`` is a mapping with:
+
+    * ``sessions`` — session rows (session_id, role, profile, pid, status,
+      last_heartbeat_at).
+    * ``leases`` — control-plane lease rows, each ideally carrying an enriched
+      ``freshness`` dict (as :func:`lease_lifecycle.list_active_leases` returns);
+      a bare string freshness is also accepted.
+    * ``terminal_lock`` — the active terminal (merge) lock, if any.
+    * ``prior_recovery_attempts`` — narrower recovery attempts already tried
+      (e.g. sanctioned reconnects) so the operator sees escalation history.
+    * ``inventory_complete`` — bool. **Must** be explicitly True; a missing or
+      falsy value forces a deny (fail closed).
+    * ``incomplete_reasons`` — optional reasons the inventory is incomplete.
+
+    The coordinator never restarts anything: ``restart_performed`` is always
+    False and the mutative apply path is a later drain-gated child.
+    """
+    moment = now or _utc_now()
+    reasons: list[str] = []
+
+    inventory_complete = bool(inventory.get("inventory_complete", False))
+    incomplete_reasons = [str(r) for r in (inventory.get("incomplete_reasons") or [])]
+
+    sessions_raw: Sequence[Mapping[str, Any]] = inventory.get("sessions") or []
+    leases_raw: Sequence[Mapping[str, Any]] = inventory.get("leases") or []
+    terminal_lock = inventory.get("terminal_lock") or None
+    prior_recovery_attempts = [
+        dict(a) for a in (inventory.get("prior_recovery_attempts") or [])
+    ]
+
+    session_impacts = [
+        _classify_session(
+            s,
+            now=moment,
+            requesting_session_id=requesting_session_id,
+            heartbeat_stale_seconds=session_heartbeat_stale_seconds,
+        )
+        for s in sessions_raw
+    ]
+    lease_impacts = [_classify_lease(l) for l in leases_raw]
+
+    # Only *other* live sessions and live leases constitute blast radius: a
+    # restart that would kill only the requesting session with no other work in
+    # flight is safe.
+    other_live_sessions = [
+        s for s in session_impacts if s.live and not s.is_requester
+    ]
+    disruptive_leases = [l for l in lease_impacts if l.disruptive]
+    critical_sections = [l for l in lease_impacts if l.is_critical_section]
+    mutations = [l for l in lease_impacts if l.is_mutation]
+
+    affected_issues = sorted(
+        {
+            l.work_number
+            for l in disruptive_leases
+            if l.work_kind == "issue" and l.work_number is not None
+        }
+    )
+    affected_prs = sorted(
+        {
+            l.work_number
+            for l in disruptive_leases
+            if l.work_kind == "pr" and l.work_number is not None
+        }
+    )
+
+    disruptive = bool(disruptive_leases or other_live_sessions or terminal_lock)
+
+    if not inventory_complete:
+        verdict = VERDICT_UNSAFE
+        allow_restart = False
+        reasons.append(
+            "inventory incomplete: restart evaluation cannot confirm blast "
+            "radius — deny (fail closed, #658)"
+        )
+        reasons.extend(incomplete_reasons)
+    elif not disruptive:
+        verdict = VERDICT_SAFE
+        allow_restart = True
+        reasons.append("no other live sessions, live leases, or terminal lock")
+    elif operator_override:
+        verdict = VERDICT_OVERRIDE
+        allow_restart = True
+        reasons.append(
+            "live work present; operator override accepts the blast radius"
+        )
+    else:
+        verdict = VERDICT_UNSAFE
+        allow_restart = False
+        reasons.append(
+            "live work would be disrupted; restart denied without operator "
+            "override"
+        )
+
+    if critical_sections and inventory_complete:
+        reasons.append(
+            f"{len(critical_sections)} critical section(s) in flight "
+            "(active lease with a live owner)"
+        )
+    if terminal_lock:
+        reasons.append("active terminal (merge) lock present")
+
+    override_would_allow = bool(inventory_complete and disruptive)
+
+    blast_radius = _blast_radius(
+        session_count=len(other_live_sessions),
+        work_count=len(affected_issues) + len(affected_prs),
+        mutation_count=len(mutations),
+    )
+
+    # Acknowledgement is a later child (drain protocol); expose per-session
+    # placeholders so the console can render the ack column now.
+    ack_state = {s.session_id: "pending" for s in other_live_sessions}
+
+    counts = {
+        "sessions_total": len(session_impacts),
+        "sessions_live_other": len(other_live_sessions),
+        "leases_total": len(lease_impacts),
+        "leases_disruptive": len(disruptive_leases),
+        "critical_sections": len(critical_sections),
+        "mutations": len(mutations),
+        "affected_issues": len(affected_issues),
+        "affected_prs": len(affected_prs),
+        "prior_recovery_attempts": len(prior_recovery_attempts),
+    }
+
+    audit_record = {
+        "event": "restart_impact_evaluated",
+        "coordinator_version": COORDINATOR_VERSION,
+        "evaluated_at": moment.isoformat(),
+        "dry_run": dry_run,
+        "operator_override": bool(operator_override),
+        "requesting_session_id": requesting_session_id,
+        "inventory_complete": inventory_complete,
+        "verdict": verdict,
+        "allow_restart": allow_restart,
+        "blast_radius": blast_radius,
+        "counts": counts,
+    }
+
+    return RestartImpactReport(
+        coordinator_version=COORDINATOR_VERSION,
+        evaluated_at=moment.isoformat(),
+        dry_run=dry_run,
+        restart_performed=False,
+        inventory_complete=inventory_complete,
+        verdict=verdict,
+        allow_restart=allow_restart,
+        override_would_allow=override_would_allow,
+        operator_override=bool(operator_override),
+        blast_radius=blast_radius,
+        reasons=reasons,
+        affected_sessions=session_impacts,
+        affected_leases=lease_impacts,
+        critical_sections=critical_sections,
+        affected_issues=affected_issues,
+        affected_prs=affected_prs,
+        mutations=mutations,
+        terminal_lock=dict(terminal_lock)
+        if isinstance(terminal_lock, Mapping)
+        else terminal_lock,
+        ack_state=ack_state,
+        prior_recovery_attempts=prior_recovery_attempts,
+        counts=counts,
+        audit_record=audit_record,
+        incomplete_reasons=incomplete_reasons,
+    )

scripts/worktree-start

@@ -43,19 +43,21 @@ repo_root="$(cd "$script_dir/.." && pwd)"
 
 # Enforce issue-linked, traceable branch names (issue → branch → worktree → PR).
 if [[ "$allow_unlinked" -eq 0 ]]; then
-  locked_branch=$(python3 -c "
+  if [[ "$dry_run" -eq 0 ]] && [[ ! "$branch" =~ ^review/pr-[0-9]+-.+ ]]; then
+    locked_branch=$(python3 -c "
 import sys
 sys.path.insert(0, '$repo_root')
 import issue_lock_store
 print(issue_lock_store.resolve_locked_branch_for_session('$branch'))
 ")
-  if [[ -z "$locked_branch" ]]; then
+    if [[ -z "$locked_branch" ]]; then
-    echo "Error: No session issue lock is bound. Call gitea_lock_issue before branch creation (fail closed)." >&2
+      echo "Error: No session issue lock is bound. Call gitea_lock_issue before branch creation (fail closed)." >&2
-    exit 2
+      exit 2
-  fi
+    fi
-  if [[ "$branch" != "$locked_branch" ]]; then
+    if [[ "$branch" != "$locked_branch" ]]; then
-    echo "Error: Requested branch '$branch' does not match locked branch '$locked_branch' (fail closed)." >&2
+      echo "Error: Requested branch '$branch' does not match locked branch '$locked_branch' (fail closed)." >&2
-    exit 2
+      exit 2
+    fi
   fi
 
   if [[ "$branch" =~ ^(fix|feat|docs|chore)/issue-[0-9]+-.+ ]] \

task_capability_map.py

@@ -41,6 +41,26 @@ TASK_CAPABILITY_MAP: dict[str, dict[str, str]] = {
         "permission": "gitea.issue.comment",
         "role": "author",
     },
+    # #860: dirty orphaned same-claimant worktree recovery (explicit operation).
+    "recover_dirty_orphaned_issue_worktree": {
+        "permission": "gitea.issue.comment",
+        "role": "author",
+    },
+    "gitea_recover_dirty_orphaned_issue_worktree": {
+        "permission": "gitea.issue.comment",
+        "role": "author",
+    },
+    # #864: dirty-preserving same-claimant author-session rebind (dead owner PID).
+    # Author MCP tool path. Reconciler execute is gated inside the tool via
+    # authorize_reconciler_execute + role_kind checks (not this map entry).
+    "rebind_dirty_same_claimant_author_session": {
+        "permission": "gitea.issue.comment",
+        "role": "author",
+    },
+    "gitea_rebind_dirty_same_claimant_author_session": {
+        "permission": "gitea.issue.comment",
+        "role": "author",
+    },
     "set_issue_labels": {
         "permission": "gitea.issue.comment",
         "role": "author",
@@ -486,6 +506,11 @@ TASK_CAPABILITY_MAP: dict[str, dict[str, str]] = {
 # merger lease (#763).
 _PREFLIGHT_TASK_TRANSITIONS = frozenset({
     ("review_pr", "acquire_reviewer_pr_lease"),
+    ("work_issue", "lock_issue"),
+    ("work_issue", "recover_dirty_orphaned_issue_worktree"),
+    ("work_issue", "gitea_recover_dirty_orphaned_issue_worktree"),
+    ("work_issue", "commit_files"),
+    ("work_issue", "gitea_commit_files"),
 })
 
 

tests/test_branch_cleanup_guard.py

@@ -1639,6 +1639,358 @@ class TestSecondRemediationIntegration(unittest.TestCase):
         self.assertTrue(ownership_calls)
 
 
+class TestIssue855ExactPrSelector(unittest.TestCase):
+    """#855: exact pr_number pin for reconcile_merged_cleanups (#851 lifecycle)."""
+
+    def setUp(self):
+        self._remotes = patch.dict(
+            mcp_server.REMOTES,
+            {
+                "prgs": {
+                    "host": "gitea.example.com",
+                    "org": "Scaled-Tech-Consulting",
+                    "repo": "Gitea-Tools",
+                }
+            },
+        )
+        self._remotes.start()
+        patch("gitea_audit.audit_enabled", return_value=False).start()
+        self.mock_api = patch("mcp_server.api_request").start()
+        self.mock_all = patch("mcp_server.api_get_all", return_value=[]).start()
+        patch("mcp_server.get_auth_header", return_value=FAKE_AUTH).start()
+        patch(
+            "mcp_server.merged_cleanup_reconcile.is_head_ancestor_of_ref",
+            return_value=True,
+        ).start()
+        patch(
+            "mcp_server.get_profile",
+            return_value=dict(RECONCILER_WITH_DELETE),
+        ).start()
+        patch(
+            "mcp_server._profile_operation_gate",
+            return_value=[],
+        ).start()
+        patch(
+            "mcp_server._collect_branch_ownership_records",
+            return_value={"records": [], "inventory_error": False},
+        ).start()
+        patch(
+            "mcp_server.merged_cleanup_reconcile.discover_reviewer_scratch_worktrees",
+            return_value=[],
+        ).start()
+        patch("mcp_server.verify_preflight_purity", return_value=None).start()
+        patch(
+            "mcp_server.audit_reconciliation_mode.check_cleanup_execution_allowed",
+            return_value=(True, []),
+        ).start()
+
+    def tearDown(self):
+        patch.stopall()
+
+    def _merged_pr(self, number, branch, sha="c" * 40):
+        return {
+            "number": number,
+            "title": f"PR {number}",
+            "body": f"Closes #{number - 4}",
+            "merged": True,
+            "merged_at": "2026-07-23T12:00:00Z",
+            "merge_commit_sha": "f" * 40,
+            "state": "closed",
+            "head": {"ref": branch, "sha": sha},
+            "base": {"ref": "master"},
+        }
+
+    def test_exact_pr_848_ignores_newer_852_in_batch_queue(self):
+        """pr_number=848 selects only #848 even when #852 is newer/first."""
+        from mcp_server import gitea_reconcile_merged_cleanups
+
+        pr_848 = self._merged_pr(
+            848, "fix/issue-844-exclude-epic-containers", sha="c3f282ba" + "0" * 32
+        )
+        # Closed list would rank #852 first in batch mode; exact pin must ignore it.
+        closed_batch = [
+            self._merged_pr(852, "fix/issue-851-cleanup-worktree-before-remote-delete"),
+            pr_848,
+            self._merged_pr(849, "fix/issue-849-other"),
+            self._merged_pr(846, "fix/issue-846-other"),
+            self._merged_pr(845, "fix/issue-845-other"),
+        ]
+        batch_fetch_calls = []
+
+        def fake_api(method, url, *args, **kwargs):
+            if method == "GET" and url.rstrip("/").endswith("/pulls/848"):
+                return dict(pr_848)
+            if method == "GET" and "/pulls/" in url:
+                raise AssertionError(f"unexpected PR fetch: {url}")
+            if method == "GET" and "/branches/" in url:
+                return {"name": "present"}
+            return {}
+
+        def fake_all(url, auth, limit=None):
+            batch_fetch_calls.append((url, limit))
+            if "state=open" in url:
+                return []
+            if "state=closed" in url:
+                # Exact mode must not use the closed batch list.
+                raise AssertionError(
+                    "exact pr_number mode must not page closed PRs: " + url
+                )
+            return []
+
+        self.mock_api.side_effect = fake_api
+        self.mock_all.side_effect = fake_all
+        patch(
+            "mcp_server._remote_branch_exists",
+            return_value=True,
+        ).start()
+        patch(
+            "mcp_server.merged_cleanup_reconcile.build_reconciliation_report",
+            side_effect=lambda **kwargs: {
+                "entries": [
+                    {
+                        "pr_number": int(pr["number"]),
+                        "head_branch": (pr.get("head") or {}).get("ref"),
+                        "issue_number": 844,
+                        "remote_branch": {
+                            "safe_to_delete_remote": True,
+                            "head_branch": (pr.get("head") or {}).get("ref"),
+                        },
+                        "local_worktree": {
+                            "safe_to_remove_worktree": True,
+                            "worktree_path": (
+                                "/tmp/branches/fix-issue-844-exclude-epic-containers"
+                            ),
+                        },
+                        "planned_execution_order": (
+                            mcp_server.merged_cleanup_reconcile.plan_cleanup_execution_order(
+                                remote_assessment={"safe_to_delete_remote": True},
+                                local_assessment={"safe_to_remove_worktree": True},
+                            )
+                        ),
+                    }
+                    for pr in kwargs.get("closed_prs") or []
+                    if pr.get("merged_at") or pr.get("merged")
+                ],
+                "reviewer_scratch_entries": [],
+                "merged_pr_count": len(kwargs.get("closed_prs") or []),
+            },
+        ).start()
+
+        res = gitea_reconcile_merged_cleanups(
+            dry_run=True,
+            pr_number=848,
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+        )
+        self.assertTrue(res.get("success"))
+        self.assertFalse(res.get("performed"))
+        self.assertEqual(res.get("selection_mode"), "exact_pr")
+        self.assertEqual(res.get("selected_pr_number"), 848)
+        entries = res.get("entries") or []
+        self.assertEqual(len(entries), 1, entries)
+        self.assertEqual(entries[0].get("pr_number"), 848)
+        self.assertEqual(
+            entries[0].get("head_branch"),
+            "fix/issue-844-exclude-epic-containers",
+        )
+        # No other PR appears in plan.
+        self.assertEqual(list((res.get("planned_execution_orders") or {}).keys()), ["848"])
+        plan = (res.get("planned_execution_orders") or {}).get("848") or []
+        actions = [s.get("action") for s in plan]
+        self.assertEqual(
+            actions,
+            [
+                "remove_local_worktree",
+                "reassess_branch_ownership",
+                "delete_remote_branch",
+            ],
+        )
+        # Prove we never scanned the multi-PR closed batch.
+        self.assertFalse(any("state=closed" in (u or "") for u, _ in batch_fetch_calls))
+        # closed_batch fixture must remain unused (sanity).
+        self.assertEqual(closed_batch[0]["number"], 852)
+
+    def test_exact_pr_execute_only_mutates_selected_pr(self):
+        """Execute with pr_number must never touch #845/#846/#849/#852."""
+        from mcp_server import gitea_reconcile_merged_cleanups
+
+        pr_848 = self._merged_pr(848, "fix/issue-844-exclude-epic-containers")
+        worktree_path = "/tmp/branches/fix-issue-844-exclude-epic-containers"
+        remove_calls = []
+        delete_api_calls = []
+        ownership_branches = []
+
+        def fake_api(method, url, *args, **kwargs):
+            if method == "GET" and url.rstrip("/").endswith("/pulls/848"):
+                return dict(pr_848)
+            if method == "DELETE":
+                delete_api_calls.append(url)
+                # Forbid foreign PR branch deletion by URL content.
+                for forbidden in ("845", "846", "849", "852"):
+                    self.assertNotIn(forbidden, url)
+            return {}
+
+        def fake_remove(project_root, branch, worktree_path=None):
+            remove_calls.append({"branch": branch, "worktree_path": worktree_path})
+            return {
+                "success": True,
+                "performed": True,
+                "message": f"removed {worktree_path}",
+                "worktree_path": worktree_path,
+            }
+
+        def fake_collect(**kwargs):
+            ownership_branches.append(kwargs.get("branch"))
+            return {"records": [], "inventory_error": False}
+
+        def fake_probe(h, o, r, auth, br):
+            return guard.classify_branch_readback_http_status(
+                404, not_found_scope=guard.NOT_FOUND_SCOPE_BRANCH
+            )
+
+        self.mock_api.side_effect = fake_api
+        self.mock_all.side_effect = lambda url, auth, limit=None: []
+        patch("mcp_server._remote_branch_exists", return_value=True).start()
+        patch(
+            "mcp_server.merged_cleanup_reconcile.build_reconciliation_report",
+            return_value={
+                "entries": [
+                    {
+                        "pr_number": 848,
+                        "head_branch": "fix/issue-844-exclude-epic-containers",
+                        "remote_branch": {"safe_to_delete_remote": True},
+                        "local_worktree": {
+                            "safe_to_remove_worktree": True,
+                            "worktree_path": worktree_path,
+                        },
+                        "planned_execution_order": [
+                            {"action": "remove_local_worktree", "phase": 1},
+                            {"action": "reassess_branch_ownership", "phase": 2},
+                            {"action": "delete_remote_branch", "phase": 3},
+                        ],
+                    }
+                ],
+                "reviewer_scratch_entries": [
+                    # Foreign scratch must be filtered before report execute loop;
+                    # if present here it would still be a test failure if acted on.
+                ],
+                "merged_pr_count": 1,
+            },
+        ).start()
+        patch(
+            "mcp_server.merged_cleanup_reconcile.remove_local_worktree",
+            side_effect=fake_remove,
+        ).start()
+        patch(
+            "mcp_server._collect_branch_ownership_records",
+            side_effect=fake_collect,
+        ).start()
+        patch("mcp_server._probe_remote_branch", side_effect=fake_probe).start()
+
+        res = gitea_reconcile_merged_cleanups(
+            dry_run=False,
+            execute_confirmed=True,
+            pr_number=848,
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+        )
+        self.assertTrue(res.get("performed") or res.get("executed"))
+        self.assertEqual(res.get("selection_mode"), "exact_pr")
+        self.assertEqual(res.get("selected_pr_number"), 848)
+        actions = res.get("actions") or []
+        pr_numbers_touched = {
+            a.get("pr_number") for a in actions if a.get("pr_number") is not None
+        }
+        self.assertTrue(pr_numbers_touched.issubset({None, 848}) or not pr_numbers_touched)
+        removes = [a for a in actions if a.get("action") == "remove_local_worktree"]
+        deletes = [a for a in actions if a.get("action") == "delete_remote_branch"]
+        self.assertEqual(len(removes), 1)
+        self.assertEqual(remove_calls[0]["branch"], "fix/issue-844-exclude-epic-containers")
+        self.assertEqual(len(deletes), 1)
+        self.assertTrue(deletes[0].get("success"))
+        self.assertTrue(deletes[0].get("after_worktree_removal"))
+        self.assertEqual(len(delete_api_calls), 1)
+        self.assertEqual(
+            ownership_branches, ["fix/issue-844-exclude-epic-containers"]
+        )
+
+    def test_exact_pr_unknown_fails_closed_without_mutation(self):
+        from mcp_server import gitea_reconcile_merged_cleanups
+
+        def fake_api(method, url, *args, **kwargs):
+            if method == "GET" and "/pulls/99999" in url:
+                raise RuntimeError("HTTP 404 Not Found")
+            raise AssertionError(f"unexpected API call {method} {url}")
+
+        self.mock_api.side_effect = fake_api
+        res = gitea_reconcile_merged_cleanups(
+            dry_run=True,
+            pr_number=99999,
+            remote="prgs",
+        )
+        self.assertFalse(res.get("success"))
+        self.assertFalse(res.get("performed"))
+        self.assertEqual(res.get("blocker_kind"), "pr_unresolvable")
+        self.assertIn("99999", " ".join(res.get("reasons") or []))
+
+    def test_exact_pr_not_merged_fails_closed(self):
+        from mcp_server import gitea_reconcile_merged_cleanups
+
+        def fake_api(method, url, *args, **kwargs):
+            if method == "GET" and url.rstrip("/").endswith("/pulls/900"):
+                return {
+                    "number": 900,
+                    "merged": False,
+                    "merged_at": None,
+                    "state": "open",
+                    "head": {"ref": "feat/x", "sha": "a" * 40},
+                }
+            raise AssertionError(f"unexpected {method} {url}")
+
+        self.mock_api.side_effect = fake_api
+        res = gitea_reconcile_merged_cleanups(
+            dry_run=False,
+            execute_confirmed=True,
+            pr_number=900,
+            remote="prgs",
+        )
+        self.assertFalse(res.get("success"))
+        self.assertFalse(res.get("performed"))
+        self.assertEqual(res.get("blocker_kind"), "pr_not_merged")
+
+    def test_exact_pr_invalid_number_fails_closed(self):
+        from mcp_server import gitea_reconcile_merged_cleanups
+
+        res = gitea_reconcile_merged_cleanups(
+            dry_run=True,
+            pr_number=0,
+            remote="prgs",
+        )
+        self.assertFalse(res.get("success"))
+        self.assertEqual(res.get("blocker_kind"), "invalid_pr_number")
+        self.mock_api.assert_not_called()
+
+    def test_batch_mode_still_works_without_pr_number(self):
+        """Unfiltered batch path remains backward compatible."""
+        from mcp_server import gitea_reconcile_merged_cleanups
+
+        self.mock_all.side_effect = lambda url, auth, limit=None: []
+        self.mock_api.side_effect = lambda *a, **k: {}
+        patch(
+            "mcp_server.merged_cleanup_reconcile.build_reconciliation_report",
+            return_value={
+                "entries": [],
+                "reviewer_scratch_entries": [],
+                "merged_pr_count": 0,
+            },
+        ).start()
+        res = gitea_reconcile_merged_cleanups(dry_run=True, remote="prgs", limit=10)
+        self.assertTrue(res.get("success"))
+        self.assertEqual(res.get("selection_mode"), "batch")
+        self.assertIsNone(res.get("selected_pr_number"))
+
 
 if __name__ == "__main__":
     unittest.main()

tests/test_dirty_orphan_worktree_recovery.py

@@ -0,0 +1,483 @@
+"""Synthetic regression coverage for dirty orphaned worktree recovery (#860).
+
+Modeled on the #850 / #855 shape without mutating their real state.
+"""
+
+from __future__ import annotations
+
+import json
+import os
+import shutil
+import tempfile
+import unittest
+from unittest import mock
+
+import dirty_orphan_worktree_recovery as dorec
+import issue_lock_store
+
+
+DEAD_PID = 999_999_999
+LIVE_PID = os.getpid()
+BRANCH = "fix/issue-901-dirty-orphan"
+SOURCE_WT = "/repo/branches/issue-901-dirty-orphan"
+RECOVERY_WT_NAME = "recovery-issue-901-dirty-orphan"
+LOCAL_HEAD = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+REMOTE_HEAD = "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb"
+OTHER_HEAD = "cccccccccccccccccccccccccccccccccccccccc"
+FP_A = dorec.sha256_bytes(b"dirty-a")
+FP_B = dorec.sha256_bytes(b"dirty-b")
+FP_C = dorec.sha256_bytes(b"dirty-c-conflict")
+
+
+def durable_lock(**overrides):
+    """#850-shaped PID-less malformed same-claimant lock."""
+    lock = {
+        "issue_number": 901,
+        "branch_name": BRANCH,
+        "worktree_path": SOURCE_WT,
+        "remote": "prgs",
+        "org": "Example-Org",
+        "repo": "Example-Repo",
+        # intentionally no pid / session_pid / work_lease expiry
+        "claimant": {"username": "author-user", "profile": "prgs-author"},
+    }
+    lock.update(overrides)
+    return lock
+
+
+def base_kwargs(**overrides):
+    kwargs = {
+        "issue_number": 901,
+        "branch_name": BRANCH,
+        "source_worktree_path": SOURCE_WT,
+        "remote": "prgs",
+        "org": "Example-Org",
+        "repo": "Example-Repo",
+        "identity": "author-user",
+        "profile": "prgs-author",
+        "expected_local_head": LOCAL_HEAD,
+        "expected_remote_head": REMOTE_HEAD,
+        "expected_dirty_fingerprints": {"a.py": FP_A, "b.py": FP_B},
+        "current_branch": BRANCH,
+        "porcelain_status": " M a.py\n M b.py\n",
+        "observed_local_head": LOCAL_HEAD,
+        "observed_remote_head": REMOTE_HEAD,
+        "observed_dirty_fingerprints": {"a.py": FP_A, "b.py": FP_B},
+        "competing_live_locks": [],
+        "competing_live_sessions": [],
+        "workflow_lease_active": False,
+        "workflow_lease_expired": True,
+        "canonical_repo_root": "/repo",
+        "worktree_registered": True,
+        "current_pid": LIVE_PID,
+    }
+    kwargs.update(overrides)
+    return kwargs
+
+
+def assess(lock=None, **overrides):
+    return dorec.assess_dirty_orphan_recovery(
+        durable_lock() if lock is None else lock, **base_kwargs(**overrides)
+    )
+
+
+class FreshnessPidLess(unittest.TestCase):
+    def test_pid_less_lock_is_not_live(self):
+        freshness = issue_lock_store.assess_lock_freshness(durable_lock())
+        self.assertFalse(freshness["live"])
+        self.assertTrue(freshness.get("pid_missing"))
+        self.assertEqual(freshness["status"], "malformed")
+
+    def test_pid_less_with_far_future_expiry_still_not_live(self):
+        lock = durable_lock(
+            work_lease={
+                "operation_type": "author_issue_work",
+                "expires_at": "2999-01-01T00:00:00Z",
+                "last_heartbeat_at": "2999-01-01T00:00:00Z",
+            }
+        )
+        freshness = issue_lock_store.assess_lock_freshness(lock)
+        self.assertFalse(freshness["live"])
+        self.assertTrue(freshness.get("pid_missing"))
+
+
+class EligibilityGranted(unittest.TestCase):
+    def test_dead_same_claimant_pid_less_dirty(self):
+        result = assess()
+        self.assertEqual(result["outcome"], dorec.ELIGIBLE)
+        self.assertTrue(result["eligible"])
+
+    def test_expired_workflow_lease_corroboration(self):
+        result = assess(workflow_lease_active=False, workflow_lease_expired=True)
+        self.assertTrue(result["eligible"])
+
+    def test_older_local_newer_remote_heads(self):
+        result = assess()
+        self.assertTrue(result["evidence"].get("heads_diverged"))
+        self.assertTrue(result["eligible"])
+
+
+class EligibilityRefused(unittest.TestCase):
+    def test_active_owner_with_pid(self):
+        lock = durable_lock(pid=LIVE_PID, session_pid=LIVE_PID)
+        result = assess(lock=lock, owner_process_alive_override=True)
+        self.assertEqual(result["outcome"], dorec.REFUSED)
+        self.assertFalse(result["eligible"])
+        self.assertTrue(any("alive" in r for r in result["reasons"]))
+
+    def test_foreign_claimant(self):
+        result = assess(identity="other-user")
+        self.assertEqual(result["outcome"], dorec.REFUSED)
+        self.assertTrue(any("foreign claimant identity" in r for r in result["reasons"]))
+
+    def test_foreign_profile(self):
+        result = assess(profile="prgs-reviewer")
+        self.assertEqual(result["outcome"], dorec.REFUSED)
+
+    def test_fingerprint_mismatch(self):
+        result = assess(observed_dirty_fingerprints={"a.py": "0" * 64, "b.py": FP_B})
+        self.assertEqual(result["outcome"], dorec.REFUSED)
+        self.assertTrue(any("fingerprint mismatch" in r for r in result["reasons"]))
+
+    def test_head_mismatch(self):
+        result = assess(observed_local_head=OTHER_HEAD)
+        self.assertEqual(result["outcome"], dorec.REFUSED)
+
+    def test_remote_head_mismatch(self):
+        result = assess(observed_remote_head=OTHER_HEAD)
+        self.assertEqual(result["outcome"], dorec.REFUSED)
+
+    def test_path_not_under_branches(self):
+        result = assess(
+            source_worktree_path="/tmp/branches/evil",
+            # lock path also changed so worktree agreement holds
+            lock=durable_lock(worktree_path="/tmp/branches/evil"),
+        )
+        self.assertEqual(result["outcome"], dorec.REFUSED)
+        self.assertTrue(any("canonical branches" in r for r in result["reasons"]))
+
+    def test_unregistered_worktree(self):
+        result = assess(worktree_registered=False)
+        self.assertEqual(result["outcome"], dorec.REFUSED)
+
+    def test_active_workflow_lease(self):
+        result = assess(workflow_lease_active=True, workflow_lease_expired=False)
+        self.assertEqual(result["outcome"], dorec.REFUSED)
+
+    def test_unsafe_dirty_path_pin(self):
+        result = assess(
+            expected_dirty_fingerprints={"../etc/passwd": FP_A},
+            observed_dirty_fingerprints={"../etc/passwd": FP_A},
+        )
+        self.assertEqual(result["outcome"], dorec.REFUSED)
+
+    def test_symlink_escape_rejected_by_ancestry(self):
+        ok, reasons = dorec.is_path_under_canonical_branches(
+            "/tmp/branches/evil", canonical_repo_root="/repo"
+        )
+        self.assertFalse(ok)
+        self.assertTrue(reasons)
+
+
+class ConflictDetection(unittest.TestCase):
+    def test_overlapping_upstream_change(self):
+        conflicts = dorec.detect_path_conflicts(
+            dirty_paths=["c.py"],
+            local_head_contents={"c.py": b"local-base"},
+            remote_head_contents={"c.py": b"remote-changed"},
+            dirty_contents={"c.py": b"dirty-c-conflict"},
+        )
+        self.assertEqual(len(conflicts), 1)
+        self.assertEqual(conflicts[0]["path"], "c.py")
+
+    def test_unchanged_upstream_no_conflict(self):
+        conflicts = dorec.detect_path_conflicts(
+            dirty_paths=["a.py"],
+            local_head_contents={"a.py": b"same"},
+            remote_head_contents={"a.py": b"same"},
+            dirty_contents={"a.py": b"dirty-a"},
+        )
+        self.assertEqual(conflicts, [])
+
+
+class CrashSafeRecovery(unittest.TestCase):
+    def setUp(self):
+        self.tmp = tempfile.mkdtemp(prefix="dirty-orphan-")
+        self.repo = os.path.join(self.tmp, "repo")
+        self.branches = os.path.join(self.repo, "branches")
+        self.source = os.path.join(self.branches, "issue-901-dirty-orphan")
+        self.recovery = os.path.join(self.branches, RECOVERY_WT_NAME)
+        os.makedirs(self.source, exist_ok=True)
+        os.makedirs(self.branches, exist_ok=True)
+        # seed dirty files in source
+        with open(os.path.join(self.source, "a.py"), "wb") as fh:
+            fh.write(b"dirty-a")
+        with open(os.path.join(self.source, "b.py"), "wb") as fh:
+            fh.write(b"dirty-b")
+        self.journal_dir = os.path.join(self.tmp, "journals")
+        self.lock = durable_lock(worktree_path=self.source)
+        self.assessment = dorec.assess_dirty_orphan_recovery(
+            self.lock,
+            **base_kwargs(
+                source_worktree_path=self.source,
+                canonical_repo_root=self.repo,
+            ),
+        )
+
+        class FakeGit(dorec.GitOps):
+            def __init__(self, recovery_path, head):
+                self.recovery_path = recovery_path
+                self.head = head
+                self.calls = []
+
+            def run(self, args, *, cwd):
+                self.calls.append((args, cwd))
+                if args[:3] == ["git", "worktree", "add"]:
+                    os.makedirs(self.recovery_path, exist_ok=True)
+                    return mock.Mock(returncode=0, stdout="", stderr="")
+                if args[:2] == ["git", "checkout"]:
+                    return mock.Mock(returncode=0, stdout="", stderr="")
+                if args[:2] == ["git", "rev-parse"]:
+                    return mock.Mock(returncode=0, stdout=self.head + "\n", stderr="")
+                return mock.Mock(returncode=0, stdout="", stderr="")
+
+        self.git = FakeGit(self.recovery, REMOTE_HEAD)
+        self.written_locks = []
+
+        def lock_writer(record):
+            self.written_locks.append(record)
+
+        self.lock_writer = lock_writer
+
+    def tearDown(self):
+        shutil.rmtree(self.tmp, ignore_errors=True)
+
+    def _run(self, **overrides):
+        kwargs = {
+            "assessment": self.assessment,
+            "existing_lock": self.lock,
+            "issue_number": 901,
+            "branch_name": BRANCH,
+            "source_worktree_path": self.source,
+            "recovery_worktree_path": self.recovery,
+            "remote": "prgs",
+            "org": "Example-Org",
+            "repo": "Example-Repo",
+            "identity": "author-user",
+            "profile": "prgs-author",
+            "expected_local_head": LOCAL_HEAD,
+            "expected_remote_head": REMOTE_HEAD,
+            "expected_dirty_fingerprints": {"a.py": FP_A, "b.py": FP_B},
+            "dirty_contents": {"a.py": b"dirty-a", "b.py": b"dirty-b"},
+            "local_head_contents": {"a.py": b"base-a", "b.py": b"base-b"},
+            "remote_head_contents": {"a.py": b"base-a", "b.py": b"base-b"},
+            "canonical_repo_root": self.repo,
+            "bind_lock": True,
+            "lock_writer": self.lock_writer,
+            "git_ops": self.git,
+            "journal_dir": self.journal_dir,
+            "session_pid": LIVE_PID,
+        }
+        kwargs.update(overrides)
+        return dorec.run_dirty_orphan_recovery(**kwargs)
+
+    def test_success_preserves_dirty_bytes_and_source(self):
+        result = self._run()
+        self.assertTrue(result["success"])
+        self.assertEqual(result["outcome"], dorec.RECOVERY_COMPLETED)
+        self.assertTrue(os.path.isdir(self.source))
+        with open(os.path.join(self.source, "a.py"), "rb") as fh:
+            self.assertEqual(fh.read(), b"dirty-a")
+        with open(os.path.join(self.recovery, "a.py"), "rb") as fh:
+            self.assertEqual(fh.read(), b"dirty-a")
+        with open(os.path.join(self.recovery, "b.py"), "rb") as fh:
+            self.assertEqual(fh.read(), b"dirty-b")
+        self.assertEqual(len(self.written_locks), 1)
+        rec = self.written_locks[0]
+        self.assertEqual(rec["session_pid"], LIVE_PID)
+        self.assertTrue(rec["dirty_orphan_recovery"]["recovered"])
+        self.assertTrue(rec["dirty_orphan_recovery"]["source_frozen"])
+
+    def test_conflict_leaves_governed_state(self):
+        result = self._run(
+            expected_dirty_fingerprints={"c.py": FP_C},
+            dirty_contents={"c.py": b"dirty-c-conflict"},
+            local_head_contents={"c.py": b"local-base"},
+            remote_head_contents={"c.py": b"remote-changed"},
+        )
+        # #860 F4: session binding is NOT finalized while conflicts remain
+        self.assertFalse(result["success"])
+        self.assertEqual(result["outcome"], dorec.CONFLICTS_PRESENT)
+        sidecar = os.path.join(self.recovery, "c.py.recovered-dirty")
+        self.assertTrue(os.path.isfile(sidecar))
+        state = os.path.join(
+            self.recovery, dorec.CONFLICT_STATE_DIR, dorec.CONFLICT_STATE_FILE
+        )
+        self.assertTrue(os.path.isfile(state))
+        with open(state, "r", encoding="utf-8") as fh:
+            payload = json.load(fh)
+        self.assertEqual(payload["resolution"], "author_edit_required")
+
+    def test_interrupt_before_journal_no_artifacts(self):
+        result = self._run(interrupt_after_phase=dorec.PHASE_ELIGIBILITY)
+        self.assertFalse(result["success"])
+        self.assertEqual(result["outcome"], "INTERRUPTED")
+        self.assertFalse(os.path.isdir(self.recovery))
+
+    def test_interrupt_after_journal_then_retry_idempotent(self):
+        first = self._run(interrupt_after_phase=dorec.PHASE_JOURNAL_PERSISTED)
+        self.assertEqual(first["outcome"], "INTERRUPTED")
+        self.assertTrue(first["journal"]["artifacts_created"]["journal"])
+        second = self._run()
+        self.assertTrue(second["success"])
+        # source still recoverable
+        with open(os.path.join(self.source, "a.py"), "rb") as fh:
+            self.assertEqual(fh.read(), b"dirty-a")
+
+    def test_interrupt_after_worktree_then_retry(self):
+        first = self._run(interrupt_after_phase=dorec.PHASE_RECOVERY_WORKTREE)
+        self.assertEqual(first["outcome"], "INTERRUPTED")
+        self.assertTrue(os.path.isdir(self.recovery))
+        second = self._run()
+        self.assertTrue(second["success"])
+
+    def test_interrupt_after_binding_then_retry_complete(self):
+        first = self._run(interrupt_after_phase=dorec.PHASE_BINDING)
+        self.assertEqual(first["outcome"], "INTERRUPTED")
+        second = self._run()
+        self.assertTrue(second["success"])
+        # completed journal makes further retries no-ops
+        third = self._run()
+        self.assertEqual(third["outcome"], dorec.RECOVERY_RESUMED)
+
+    def test_source_worktree_never_deleted(self):
+        self._run()
+        self.assertTrue(os.path.isdir(self.source))
+        self.assertTrue(os.path.isfile(os.path.join(self.source, "a.py")))
+
+    def test_fingerprint_drift_refuses_without_mutation(self):
+        result = self._run(dirty_contents={"a.py": b"CHANGED", "b.py": b"dirty-b"})
+        self.assertFalse(result["success"])
+        self.assertFalse(os.path.isdir(self.recovery))
+
+
+class SessionBindingPreflight(unittest.TestCase):
+    def test_canonical_session_binding_recognized(self):
+        lock = {
+            "worktree_path": "/repo/branches/recovery",
+            "session_pid": LIVE_PID,
+            "dirty_orphan_recovery": {
+                "recovered": True,
+                "conflicts": [],
+                "recovery_worktree_path": "/repo/branches/recovery",
+                "source_worktree_path": SOURCE_WT,
+                "accepted_head": REMOTE_HEAD,
+            },
+        }
+        result = dorec.preflight_recognizes_recovered_provenance(lock)
+        self.assertTrue(result["recognized"])
+
+    def test_conflicts_block_commit_preflight(self):
+        lock = {
+            "worktree_path": "/repo/branches/recovery",
+            "session_pid": LIVE_PID,
+            "dirty_orphan_recovery": {
+                "recovered": True,
+                "conflicts": [{"path": "c.py"}],
+            },
+        }
+        result = dorec.preflight_recognizes_recovered_provenance(lock)
+        self.assertFalse(result["recognized"])
+
+    def test_active_foreign_does_not_mutate(self):
+        # assess-only path: foreign refused before run
+        result = assess(identity="intruder")
+        self.assertFalse(result["eligible"])
+
+
+class JournalSymlinkRefusal(unittest.TestCase):
+    def test_symlink_journal_path_refused_on_load(self):
+        tmp = tempfile.mkdtemp()
+        try:
+            real = os.path.join(tmp, "real.json")
+            with open(real, "w", encoding="utf-8") as fh:
+                fh.write("{}")
+            link = os.path.join(tmp, "link.json")
+            os.symlink(real, link)
+            key = "symlink-test"
+            jdir = tmp
+            path = dorec._journal_path(key, journal_dir=jdir)
+            with open(path, "w", encoding="utf-8") as fh:
+                json.dump({"idempotency_key": key}, fh)
+            os.remove(path)
+            os.symlink(real, path)
+            with self.assertRaises(ValueError):
+                dorec.load_journal(key, journal_dir=jdir)
+        finally:
+            shutil.rmtree(tmp, ignore_errors=True)
+
+
+class RealGitMultiWorktreeIntegration(unittest.TestCase):
+    def setUp(self):
+        import subprocess
+        self.tmp = tempfile.mkdtemp(prefix="git-integration-")
+        self.repo = os.path.join(self.tmp, "repo")
+        os.makedirs(self.repo, exist_ok=True)
+        subprocess.run(["git", "init"], cwd=self.repo, check=True, capture_output=True)
+        subprocess.run(["git", "config", "user.name", "Test User"], cwd=self.repo, check=True)
+        subprocess.run(["git", "config", "user.email", "[email protected]"], cwd=self.repo, check=True)
+        with open(os.path.join(self.repo, "init.txt"), "w") as fh:
+            fh.write("init")
+        subprocess.run(["git", "add", "."], cwd=self.repo, check=True)
+        subprocess.run(["git", "commit", "-m", "init"], cwd=self.repo, check=True)
+        branch = "fix/issue-999-test"
+        subprocess.run(["git", "branch", branch], cwd=self.repo, check=True)
+        self.branches = os.path.join(self.repo, "branches")
+        self.source = os.path.join(self.branches, "issue-999-test")
+        subprocess.run(["git", "worktree", "add", self.source, branch], cwd=self.repo, check=True)
+        self.dirty_path = os.path.join(self.source, "dirty.txt")
+        with open(self.dirty_path, "w") as fh:
+            fh.write("dirty-data")
+
+    def tearDown(self):
+        shutil.rmtree(self.tmp, ignore_errors=True)
+
+    def test_prepare_recovery_worktree_detached_no_exit_128(self):
+        import subprocess
+        head_sha = subprocess.check_output(["git", "rev-parse", "HEAD"], cwd=self.repo, text=True).strip()
+        rec_wt = os.path.join(self.branches, "recovery-issue-999-test")
+        res = dorec.prepare_recovery_worktree(
+            canonical_repo_root=self.repo,
+            recovery_worktree_path=rec_wt,
+            branch_name="fix/issue-999-test",
+            remote_head=head_sha,
+        )
+        self.assertTrue(res["success"], res.get("reasons"))
+        self.assertTrue(os.path.isdir(rec_wt))
+
+    def test_real_lock_rebind_recovery_sanctioned(self):
+        lock_dir = os.path.join(self.tmp, "locks")
+        rec_wt = os.path.join(self.branches, "recovery-issue-999-test")
+        os.makedirs(rec_wt, exist_ok=True)
+        record = {
+            "remote": "prgs",
+            "org": "Example-Org",
+            "repo": "Example-Repo",
+            "issue_number": 999,
+            "branch_name": "fix/issue-999-test",
+            "worktree_path": rec_wt,
+            "claimant": {"username": "author-user", "profile": "prgs-author"},
+        }
+        record_src = dict(record)
+        record_src["worktree_path"] = self.source
+        issue_lock_store.bind_session_lock(record_src, lock_dir=lock_dir)
+        path = issue_lock_store.bind_session_lock(
+            record,
+            lock_dir=lock_dir,
+            recovery_sanctioned=True,
+        )
+        self.assertTrue(os.path.isfile(path))
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_issue_855_expired_reviewer_reclaim.py

@@ -0,0 +1,244 @@
+"""#855 AC4: an expired reviewer lease must not indefinitely protect an
+already-merged branch when no live claimant exists.
+
+Two layers are covered:
+
+* ``branch_cleanup_guard.assess_expired_reviewer_lease_reclaim`` — the pure,
+  fail-closed reclaim decision. Every condition must be provably satisfied or
+  the lease keeps protecting the branch.
+* ``gitea_mcp_server._collect_branch_ownership_records`` — the wiring that
+  supplies authoritative evidence (PR merged state, owner-process liveness,
+  competing ownership) to that decision, and flips an expired reviewer lease
+  to reclaimable only under the full policy.
+
+All inputs are fabricated; no real repository, lease, or credential is used.
+"""
+
+import importlib
+import unittest
+from unittest.mock import patch
+
+import branch_cleanup_guard
+
+mcp_server = importlib.import_module("gitea_mcp_server")
+
+FAKE_AUTH = "token fake"
+REMOTE = "prgs"
+ORG = "Scaled-Tech-Consulting"
+REPO = "Gitea-Tools"
+HOST = "gitea.prgs.cc"
+BRANCH = "feat/issue-638-webui-app-shell-phase1"
+PR_NUMBER = 818
+
+
+class TestAssessExpiredReviewerLeaseReclaim(unittest.TestCase):
+    """Pure fail-closed reclaim decision (#855 AC4)."""
+
+    def _call(self, **overrides):
+        base = dict(
+            role="reviewer",
+            status="expired",
+            pr_merged=True,
+            owner_pid_alive=False,
+            competing_active_claimant=False,
+        )
+        base.update(overrides)
+        return branch_cleanup_guard.assess_expired_reviewer_lease_reclaim(**base)
+
+    def test_full_policy_satisfied_allows_reclaim(self):
+        out = self._call()
+        self.assertTrue(out["reclaim_allowed"])
+        self.assertEqual(out["reasons"], [])
+        self.assertEqual(out["decision"], "reclaim_expired_reviewer_lease")
+
+    def test_stale_dead_process_reviewer_also_reclaimable(self):
+        out = self._call(status="stale_dead_process")
+        self.assertTrue(out["reclaim_allowed"])
+
+    def test_non_reviewer_role_never_reclaims(self):
+        for role in ("author", "merger", "controller", "reconciler", "unknown"):
+            with self.subTest(role=role):
+                out = self._call(role=role)
+                self.assertFalse(out["reclaim_allowed"])
+                self.assertTrue(out["reasons"])
+                self.assertEqual(out["decision"], "keep_protecting")
+
+    def test_active_status_never_reclaims(self):
+        out = self._call(status="active")
+        self.assertFalse(out["reclaim_allowed"])
+
+    def test_pr_not_merged_blocks_reclaim(self):
+        out = self._call(pr_merged=False)
+        self.assertFalse(out["reclaim_allowed"])
+
+    def test_pr_merged_unknown_fails_closed(self):
+        out = self._call(pr_merged=None)
+        self.assertFalse(out["reclaim_allowed"])
+
+    def test_owner_process_alive_blocks_reclaim(self):
+        out = self._call(owner_pid_alive=True)
+        self.assertFalse(out["reclaim_allowed"])
+
+    def test_owner_liveness_unknown_fails_closed(self):
+        out = self._call(owner_pid_alive=None)
+        self.assertFalse(out["reclaim_allowed"])
+
+    def test_competing_active_claimant_blocks_reclaim(self):
+        out = self._call(competing_active_claimant=True)
+        self.assertFalse(out["reclaim_allowed"])
+
+    def test_competing_claimant_unknown_fails_closed(self):
+        out = self._call(competing_active_claimant=None)
+        self.assertFalse(out["reclaim_allowed"])
+
+    def test_reasons_never_leak_secrets(self):
+        out = self._call(role="author")
+        blob = " ".join(out["reasons"]).lower()
+        self.assertNotIn("token", blob)
+        self.assertNotIn("password", blob)
+
+
+class _FakeLease(dict):
+    pass
+
+
+class TestCollectorExpiredReviewerReclaimWiring(unittest.TestCase):
+    """`_collect_branch_ownership_records` supplies authoritative evidence and
+    flips an expired reviewer lease to reclaimable only under the full policy."""
+
+    def _run(
+        self,
+        *,
+        lease_role="reviewer",
+        lease_freshness="stale_dead_process",
+        owner_pid_alive=False,
+        pr_merged=True,
+        extra_leases=None,
+        worktree_on_branch=False,
+    ):
+        lease = _FakeLease(
+            role=lease_role,
+            work_kind="pr",
+            work_number=PR_NUMBER,
+            branch=BRANCH,
+            status="active",
+            owner_pid=999999,
+            remote=REMOTE,
+            org=ORG,
+            repo=REPO,
+            host=HOST,
+            freshness={
+                "freshness": lease_freshness,
+                "owner_pid": 999999,
+                "owner_pid_alive": owner_pid_alive,
+                "expired_by_time": lease_freshness == "expired",
+            },
+        )
+        leases = [lease] + list(extra_leases or [])
+
+        pr_payload = {
+            "number": PR_NUMBER,
+            "merged": pr_merged,
+            "merged_at": "2026-07-23T00:00:00Z" if pr_merged else None,
+            "head": {"ref": BRANCH},
+        }
+
+        def fake_api_request(method, url, *a, **k):
+            if method == "GET" and f"/pulls/{PR_NUMBER}" in url:
+                return pr_payload
+            raise AssertionError(f"unexpected api_request {method} {url}")
+
+        wt_entries = []
+        if worktree_on_branch:
+            wt_entries = [{"branch": BRANCH, "path": f"/x/branches/{BRANCH}"}]
+
+        with patch.object(
+            mcp_server.lease_lifecycle,
+            "list_active_leases",
+            return_value={"leases": leases},
+        ), patch.object(
+            mcp_server.control_plane_db, "get_db", return_value=object(), create=True
+        ), patch.object(
+            mcp_server.issue_lock_store, "iter_lock_files", return_value=[]
+        ), patch.object(
+            mcp_server.worktree_cleanup_audit,
+            "list_worktrees",
+            return_value=wt_entries,
+        ), patch.object(
+            mcp_server, "api_get_all", return_value=[]
+        ), patch.object(
+            mcp_server, "api_request", side_effect=fake_api_request
+        ):
+            return mcp_server._collect_branch_ownership_records(
+                remote=REMOTE,
+                host=HOST,
+                org=ORG,
+                repo=REPO,
+                branch=BRANCH,
+                pr_number=PR_NUMBER,
+                project_root="/x",
+                auth=FAKE_AUTH,
+                base_api="https://gitea.prgs.cc/api/v1/repos/x/y",
+            )
+
+    def _reviewer_records(self, bundle):
+        return [
+            rec
+            for rec in bundle["records"]
+            if rec.get("category")
+            == branch_cleanup_guard.OWNERSHIP_CATEGORY_REVIEWER_LEASE
+        ]
+
+    def test_merged_dead_uncontested_reviewer_lease_is_reclaimable(self):
+        bundle = self._run()
+        self.assertFalse(bundle["inventory_error"])
+        recs = self._reviewer_records(bundle)
+        self.assertEqual(len(recs), 1)
+        self.assertTrue(recs[0]["reclaim_allowed"])
+        # And the guard consequently does not block deletion on it.
+        ownership = branch_cleanup_guard.assess_active_branch_ownership(
+            remote=REMOTE, org=ORG, repo=REPO, branch=BRANCH, host=HOST,
+            records=bundle["records"],
+        )
+        self.assertFalse(ownership["block"])
+
+    def test_unmerged_pr_keeps_reviewer_lease_protective(self):
+        bundle = self._run(pr_merged=False)
+        recs = self._reviewer_records(bundle)
+        self.assertEqual(len(recs), 1)
+        self.assertFalse(recs[0]["reclaim_allowed"])
+        ownership = branch_cleanup_guard.assess_active_branch_ownership(
+            remote=REMOTE, org=ORG, repo=REPO, branch=BRANCH, host=HOST,
+            records=bundle["records"],
+        )
+        self.assertTrue(ownership["block"])
+
+    def test_owner_process_alive_keeps_reviewer_lease_protective(self):
+        bundle = self._run(owner_pid_alive=True, lease_freshness="expired")
+        recs = self._reviewer_records(bundle)
+        self.assertFalse(recs[0]["reclaim_allowed"])
+
+    def test_competing_worktree_binding_keeps_reviewer_lease_protective(self):
+        bundle = self._run(worktree_on_branch=True)
+        recs = self._reviewer_records(bundle)
+        self.assertFalse(recs[0]["reclaim_allowed"])
+        ownership = branch_cleanup_guard.assess_active_branch_ownership(
+            remote=REMOTE, org=ORG, repo=REPO, branch=BRANCH, host=HOST,
+            records=bundle["records"],
+        )
+        self.assertTrue(ownership["block"])
+
+    def test_expired_author_lease_never_reclaimed_by_reviewer_policy(self):
+        bundle = self._run(lease_role="author")
+        author_recs = [
+            rec
+            for rec in bundle["records"]
+            if rec.get("category")
+            == branch_cleanup_guard.OWNERSHIP_CATEGORY_AUTHOR_LEASE
+        ]
+        self.assertEqual(len(author_recs), 1)
+        self.assertFalse(author_recs[0]["reclaim_allowed"])
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_issue_858_audit_merged_pr_aware.py

@@ -0,0 +1,551 @@
+"""Merged-PR awareness for the worktree cleanup audit (#858).
+
+Before #858 an ``issue_work`` worktree could never leave ``active_issue_work``:
+the audit had no PR linkage at all (``pr_number`` was structurally ``None``)
+and its only route to ``clean_stale_removable`` was a TTL derived from a
+``last_used_at`` that nothing ever populated. A merged, clean, unprotected
+worktree was therefore reported as active work forever, disagreeing with the
+PR-scoped reconciler.
+
+These tests use fabricated temporary repositories and synthetic PR records
+only. Nothing here removes a worktree or deletes a branch.
+"""
+
+import os
+import subprocess
+import sys
+import tempfile
+import unittest
+from unittest.mock import patch
+
+sys.path.insert(0, str(__import__("pathlib").Path(__file__).resolve().parent.parent))
+
+import merged_cleanup_reconcile as mcr  # noqa: E402
+import worktree_cleanup_audit as wca  # noqa: E402
+
+
+MERGED_BRANCH = "feat/issue-777-timeline"
+MERGED_PATH = "/repo/branches/issue-777-timeline"
+HEAD_SHA = "a" * 40
+
+
+def _pr(number, branch, *, merged=True, sha=HEAD_SHA, state=None):
+    """Synthetic Gitea PR payload."""
+    return {
+        "number": number,
+        "head": {"ref": branch, "sha": sha},
+        "merged_at": "2026-07-24T01:00:00Z" if merged else None,
+        "state": state or ("closed" if merged else "open"),
+    }
+
+
+def _porcelain(*entries):
+    out = []
+    for path, branch, sha in entries:
+        out.append(f"worktree {path}")
+        out.append(f"HEAD {sha}")
+        if branch is None:
+            out.append("detached")
+        else:
+            out.append(f"branch refs/heads/{branch}")
+        out.append("")
+    return "\n".join(out)
+
+
+class _AuditHarness(unittest.TestCase):
+    """Runs audit_branches_directory over a fabricated worktree listing."""
+
+    PORCELAIN = _porcelain(
+        ("/repo", "master", "f" * 40),
+        (MERGED_PATH, MERGED_BRANCH, HEAD_SHA),
+    )
+
+    def run_audit(self, *, dirty_paths=(), contained=True, **kwargs):
+        def fake_dirty(path):
+            if path in dirty_paths:
+                return {"exists": True, "dirty": True, "dirty_files": [" M x.py"]}
+            return {"exists": True, "dirty": False, "dirty_files": []}
+
+        with patch.object(
+            wca, "list_worktrees",
+            return_value=wca.parse_worktree_porcelain(self.PORCELAIN),
+        ), patch.object(
+            wca, "read_worktree_dirty", side_effect=fake_dirty
+        ), patch.object(
+            wca, "git_worktree_list", return_value="(mocked)"
+        ), patch.object(
+            wca, "is_head_ancestor_of_ref", return_value=contained
+        ):
+            report = wca.audit_branches_directory("/repo", **kwargs)
+        return {wt["path"]: wt for wt in report["worktrees"]}, report
+
+    def merged_audit(self, **kwargs):
+        kwargs.setdefault("pr_index", wca.build_pr_index([_pr(849, MERGED_BRANCH)]))
+        kwargs.setdefault("master_ref", "prgs/master")
+        return self.run_audit(**kwargs)
+
+
+class TestMergedWorktreeBecomesRemovable(_AuditHarness):
+    def test_clean_merged_issue_worktree_is_linked_and_removable(self):
+        by_path, report = self.merged_audit()
+        entry = by_path[MERGED_PATH]
+
+        self.assertEqual(entry["classification"], wca.CLASS_CLEAN_STALE_REMOVABLE)
+        self.assertTrue(entry["removable"])
+        self.assertEqual(entry["merged_pr_linkage"]["status"], wca.LINKAGE_MERGED)
+        self.assertEqual(entry["merged_pr_cleanup"]["block_reasons"], [])
+        self.assertIn(MERGED_PATH, [c["path"] for c in report["removable_candidates"]])
+
+    def test_pr_number_populated_from_authoritative_linkage(self):
+        by_path, _ = self.merged_audit()
+        self.assertEqual(by_path[MERGED_PATH]["pr_number"], 849)
+
+    def test_regression_without_pr_evidence_stays_active_issue_work(self):
+        """The pre-#858 behaviour, still correct when no PR state is supplied."""
+        by_path, _ = self.run_audit()
+        entry = by_path[MERGED_PATH]
+        self.assertEqual(entry["classification"], wca.CLASS_ACTIVE_ISSUE_WORK)
+        self.assertFalse(entry["removable"])
+        self.assertIsNone(entry["pr_number"])
+
+
+class TestProtectiveSignalsSurvive(_AuditHarness):
+    def test_open_pr_worktree_is_not_removable(self):
+        index = wca.build_pr_index([_pr(900, MERGED_BRANCH, merged=False)])
+        by_path, _ = self.run_audit(
+            pr_index=index,
+            master_ref="prgs/master",
+            open_pr_branches={MERGED_BRANCH},
+        )
+        entry = by_path[MERGED_PATH]
+        self.assertEqual(entry["classification"], wca.CLASS_ACTIVE_OPEN_PR)
+        self.assertFalse(entry["removable"])
+        # linkage still reports the owning PR, it just is not merge proof
+        self.assertEqual(entry["merged_pr_linkage"]["status"], wca.LINKAGE_OPEN)
+        self.assertEqual(entry["pr_number"], 900)
+
+    def test_dirty_tracked_worktree_is_not_removable(self):
+        by_path, _ = self.merged_audit(dirty_paths=(MERGED_PATH,))
+        entry = by_path[MERGED_PATH]
+        self.assertEqual(entry["classification"], wca.CLASS_DIRTY_LOCAL)
+        self.assertFalse(entry["removable"])
+        self.assertIn(
+            "worktree has uncommitted changes",
+            entry["merged_pr_cleanup"]["block_reasons"],
+        )
+
+    def test_untracked_only_worktree_is_not_removable(self):
+        """``git status --porcelain`` reports untracked files as dirty too."""
+        def untracked(path):
+            if path == MERGED_PATH:
+                return {"exists": True, "dirty": True, "dirty_files": ["?? scratch.txt"]}
+            return {"exists": True, "dirty": False, "dirty_files": []}
+
+        with patch.object(
+            wca, "list_worktrees",
+            return_value=wca.parse_worktree_porcelain(self.PORCELAIN),
+        ), patch.object(
+            wca, "read_worktree_dirty", side_effect=untracked
+        ), patch.object(
+            wca, "git_worktree_list", return_value="(mocked)"
+        ), patch.object(
+            wca, "is_head_ancestor_of_ref", return_value=True
+        ):
+            report = wca.audit_branches_directory(
+                "/repo",
+                pr_index=wca.build_pr_index([_pr(849, MERGED_BRANCH)]),
+                master_ref="prgs/master",
+            )
+        entry = {wt["path"]: wt for wt in report["worktrees"]}[MERGED_PATH]
+        self.assertEqual(entry["classification"], wca.CLASS_DIRTY_LOCAL)
+        self.assertFalse(entry["removable"])
+
+    def test_active_lease_by_issue_number_is_protective(self):
+        by_path, _ = self.merged_audit(leased_issue_numbers={777})
+        entry = by_path[MERGED_PATH]
+        self.assertTrue(entry["has_active_lease"])
+        self.assertEqual(entry["classification"], wca.CLASS_ACTIVE_ISSUE_WORK)
+        self.assertFalse(entry["removable"])
+
+    def test_active_lease_by_branch_is_protective(self):
+        by_path, _ = self.merged_audit(leased_branches={MERGED_BRANCH})
+        entry = by_path[MERGED_PATH]
+        self.assertTrue(entry["has_active_lease"])
+        self.assertFalse(entry["removable"])
+
+    def test_active_issue_lock_is_protective(self):
+        by_path, _ = self.merged_audit(active_issue_branches={MERGED_BRANCH})
+        entry = by_path[MERGED_PATH]
+        self.assertTrue(entry["has_active_issue_lock"])
+        self.assertEqual(entry["classification"], wca.CLASS_ACTIVE_ISSUE_WORK)
+        self.assertFalse(entry["removable"])
+
+    def test_live_session_worktree_is_protective(self):
+        by_path, _ = self.merged_audit(live_session_paths={MERGED_PATH})
+        entry = by_path[MERGED_PATH]
+        self.assertTrue(entry["has_live_session"])
+        self.assertEqual(entry["classification"], wca.CLASS_ACTIVE_ISSUE_WORK)
+        self.assertFalse(entry["removable"])
+
+    def test_head_not_contained_in_master_is_not_removable(self):
+        by_path, _ = self.merged_audit(contained=False)
+        entry = by_path[MERGED_PATH]
+        self.assertEqual(entry["classification"], wca.CLASS_ACTIVE_ISSUE_WORK)
+        self.assertFalse(entry["removable"])
+        self.assertIn(
+            "worktree head is not contained in authoritative master "
+            "(unmerged commits remain)",
+            entry["merged_pr_cleanup"]["block_reasons"],
+        )
+
+    def test_unknown_containment_fails_closed(self):
+        by_path, _ = self.merged_audit(contained=None)
+        entry = by_path[MERGED_PATH]
+        self.assertFalse(entry["removable"])
+        self.assertIn(
+            "containment of the worktree head in master is unknown",
+            entry["merged_pr_cleanup"]["block_reasons"],
+        )
+
+    def test_missing_master_ref_fails_closed(self):
+        by_path, _ = self.run_audit(
+            pr_index=wca.build_pr_index([_pr(849, MERGED_BRANCH)])
+        )
+        self.assertFalse(by_path[MERGED_PATH]["removable"])
+
+    def test_unmerged_owning_pr_is_not_removable(self):
+        index = wca.build_pr_index([_pr(901, MERGED_BRANCH, merged=False)])
+        by_path, _ = self.run_audit(pr_index=index, master_ref="prgs/master")
+        entry = by_path[MERGED_PATH]
+        self.assertFalse(entry["removable"])
+        self.assertIn(
+            "owning PR #901 is not merged",
+            entry["merged_pr_cleanup"]["block_reasons"],
+        )
+
+    def test_control_checkout_is_never_removable(self):
+        by_path, _ = self.merged_audit()
+        control = by_path["/repo"]
+        self.assertTrue(control["is_protected"])
+        self.assertEqual(control["classification"], wca.CLASS_UNSAFE_UNKNOWN)
+        self.assertFalse(control["removable"])
+
+    def test_control_checkout_not_removable_even_if_linked_and_merged(self):
+        """A merged PR on the control checkout must not unlock removal."""
+        porcelain = _porcelain(("/repo", MERGED_BRANCH, HEAD_SHA))
+        with patch.object(
+            wca, "list_worktrees", return_value=wca.parse_worktree_porcelain(porcelain)
+        ), patch.object(
+            wca, "read_worktree_dirty",
+            return_value={"exists": True, "dirty": False, "dirty_files": []},
+        ), patch.object(
+            wca, "git_worktree_list", return_value="(mocked)"
+        ), patch.object(
+            wca, "is_head_ancestor_of_ref", return_value=True
+        ):
+            report = wca.audit_branches_directory(
+                "/repo",
+                pr_index=wca.build_pr_index([_pr(849, MERGED_BRANCH)]),
+                master_ref="prgs/master",
+            )
+        entry = report["worktrees"][0]
+        self.assertEqual(entry["classification"], wca.CLASS_UNSAFE_UNKNOWN)
+        self.assertFalse(entry["removable"])
+
+
+class TestAmbiguousLinkageFailsClosed(_AuditHarness):
+    def test_competing_prs_on_one_branch_fail_closed(self):
+        index = wca.build_pr_index(
+            [_pr(849, MERGED_BRANCH), _pr(860, MERGED_BRANCH)]
+        )
+        by_path, _ = self.run_audit(pr_index=index, master_ref="prgs/master")
+        entry = by_path[MERGED_PATH]
+        self.assertEqual(entry["merged_pr_linkage"]["status"], wca.LINKAGE_AMBIGUOUS)
+        self.assertIsNone(entry["pr_number"])
+        self.assertEqual(entry["classification"], wca.CLASS_ACTIVE_ISSUE_WORK)
+        self.assertFalse(entry["removable"])
+
+    def test_merged_plus_open_pr_on_one_branch_fails_closed(self):
+        index = wca.build_pr_index(
+            [_pr(849, MERGED_BRANCH), _pr(861, MERGED_BRANCH, merged=False)]
+        )
+        by_path, _ = self.run_audit(pr_index=index, master_ref="prgs/master")
+        entry = by_path[MERGED_PATH]
+        self.assertEqual(entry["merged_pr_linkage"]["status"], wca.LINKAGE_AMBIGUOUS)
+        self.assertFalse(entry["removable"])
+
+    def test_no_owning_pr_fails_closed(self):
+        by_path, _ = self.run_audit(
+            pr_index=wca.build_pr_index([_pr(849, "feat/other-branch")]),
+            master_ref="prgs/master",
+        )
+        entry = by_path[MERGED_PATH]
+        self.assertEqual(entry["merged_pr_linkage"]["status"], wca.LINKAGE_NONE)
+        self.assertFalse(entry["removable"])
+
+    def test_malformed_pr_records_are_dropped_not_guessed(self):
+        index = wca.build_pr_index(
+            [
+                {"number": None, "head": {"ref": MERGED_BRANCH}},
+                {"number": 5, "head": {}},
+                {"number": "not-an-int", "head": {"ref": MERGED_BRANCH}},
+            ]
+        )
+        self.assertEqual(index, {})
+        self.assertEqual(
+            wca.resolve_owning_pr(branch=MERGED_BRANCH, pr_index=index)["status"],
+            wca.LINKAGE_NONE,
+        )
+
+    def test_detached_worktree_has_no_branch_linkage(self):
+        self.assertEqual(
+            wca.resolve_owning_pr(branch=None, pr_index={})["status"],
+            wca.LINKAGE_UNKNOWN,
+        )
+
+
+class TestUnrelatedClassificationsUnchanged(unittest.TestCase):
+    """Non-issue_work worktrees keep their pre-#858 classifications."""
+
+    PORCELAIN = _porcelain(
+        ("/repo", "master", "f" * 40),
+        ("/repo/branches/review-pr42", "review-pr42", "2" * 40),
+        ("/repo/branches/baseline-master-x", "baseline-master-x", "3" * 40),
+        ("/repo/branches/conflict-fix-pr50", "conflict-fix-pr50", "4" * 40),
+        ("/repo/branches/review-pr99", None, "5" * 40),
+    )
+
+    def _audit(self, **kwargs):
+        with patch.object(
+            wca, "list_worktrees",
+            return_value=wca.parse_worktree_porcelain(self.PORCELAIN),
+        ), patch.object(
+            wca, "read_worktree_dirty",
+            return_value={"exists": True, "dirty": False, "dirty_files": []},
+        ), patch.object(
+            wca, "git_worktree_list", return_value="(mocked)"
+        ), patch.object(
+            wca, "is_head_ancestor_of_ref", return_value=True
+        ):
+            report = wca.audit_branches_directory("/repo", **kwargs)
+        return {wt["path"]: wt for wt in report["worktrees"]}
+
+    def test_classifications_identical_with_and_without_pr_evidence(self):
+        without = self._audit()
+        with_evidence = self._audit(
+            pr_index=wca.build_pr_index([_pr(849, MERGED_BRANCH)]),
+            master_ref="prgs/master",
+        )
+        self.assertEqual(
+            {p: e["classification"] for p, e in without.items()},
+            {p: e["classification"] for p, e in with_evidence.items()},
+        )
+
+    def test_lease_on_issue_does_not_capture_similarly_named_scratch_trees(self):
+        """A lease on issue 777 protects issue work, not baseline/review trees."""
+        porcelain = _porcelain(
+            ("/repo/branches/baseline-master-issue-777", "baseline-issue-777", "7" * 40),
+            ("/repo/branches/issue-777-timeline", MERGED_BRANCH, HEAD_SHA),
+        )
+        with patch.object(
+            wca, "list_worktrees", return_value=wca.parse_worktree_porcelain(porcelain)
+        ), patch.object(
+            wca, "read_worktree_dirty",
+            return_value={"exists": True, "dirty": False, "dirty_files": []},
+        ), patch.object(
+            wca, "git_worktree_list", return_value="(mocked)"
+        ), patch.object(
+            wca, "is_head_ancestor_of_ref", return_value=True
+        ):
+            report = wca.audit_branches_directory(
+                "/repo",
+                pr_index=wca.build_pr_index([_pr(849, MERGED_BRANCH)]),
+                master_ref="prgs/master",
+                leased_issue_numbers={777},
+            )
+        by_path = {wt["path"]: wt for wt in report["worktrees"]}
+
+        baseline = by_path["/repo/branches/baseline-master-issue-777"]
+        self.assertFalse(baseline["has_active_lease"])
+        self.assertEqual(baseline["classification"], wca.CLASS_CLEAN_STALE_REMOVABLE)
+
+        issue_work = by_path["/repo/branches/issue-777-timeline"]
+        self.assertTrue(issue_work["has_active_lease"])
+        self.assertFalse(issue_work["removable"])
+
+    def test_review_and_baseline_still_removable(self):
+        by_path = self._audit(
+            pr_index=wca.build_pr_index([]), master_ref="prgs/master"
+        )
+        self.assertEqual(
+            by_path["/repo/branches/review-pr42"]["classification"],
+            wca.CLASS_CLEAN_STALE_REMOVABLE,
+        )
+        self.assertEqual(
+            by_path["/repo/branches/baseline-master-x"]["classification"],
+            wca.CLASS_CLEAN_STALE_REMOVABLE,
+        )
+        self.assertEqual(
+            by_path["/repo/branches/review-pr99"]["classification"],
+            wca.CLASS_DETACHED_REVIEW_LEFTOVER,
+        )
+
+    def test_conflict_fix_ttl_behaviour_unchanged(self):
+        """conflict_fix still needs only TTL expiry; #858 did not touch it."""
+        self.assertEqual(
+            wca.classify_worktree(
+                workflow_type=wca.WORKFLOW_CONFLICT_FIX,
+                is_dirty=False,
+                ttl_expired=True,
+            ),
+            wca.CLASS_CLEAN_STALE_REMOVABLE,
+        )
+        self.assertEqual(
+            wca.classify_worktree(
+                workflow_type=wca.WORKFLOW_CONFLICT_FIX,
+                is_dirty=False,
+                ttl_expired=False,
+            ),
+            wca.CLASS_ACTIVE_ISSUE_WORK,
+        )
+
+    def test_issue_work_ttl_alone_no_longer_grants_removal(self):
+        """Age is not landing proof: TTL alone must not reclaim issue work."""
+        self.assertEqual(
+            wca.classify_worktree(
+                workflow_type=wca.WORKFLOW_ISSUE_WORK,
+                is_dirty=False,
+                ttl_expired=True,
+            ),
+            wca.CLASS_ACTIVE_ISSUE_WORK,
+        )
+
+
+class TestAssessorPerformsNoDeletion(_AuditHarness):
+    def test_audit_never_removes_a_worktree(self):
+        with patch.object(wca, "remove_worktree") as removal:
+            self.merged_audit()
+        removal.assert_not_called()
+
+    def test_audit_shells_out_to_no_destructive_git_command(self):
+        seen = []
+        real_run = subprocess.run
+
+        def recording_run(cmd, *args, **kwargs):
+            seen.append(cmd)
+            return real_run(["true"], *args, **kwargs)
+
+        with patch.object(subprocess, "run", side_effect=recording_run):
+            wca.audit_branches_directory("/nonexistent-repo-for-audit")
+
+        joined = [" ".join(c) if isinstance(c, list) else str(c) for c in seen]
+        for cmd in joined:
+            self.assertNotIn("worktree remove", cmd)
+            self.assertNotIn("branch -D", cmd)
+            self.assertNotIn("push", cmd)
+
+
+class TestAgreementWithPrScopedReconciler(unittest.TestCase):
+    """The audit and merged_cleanup_reconcile must agree on identical input.
+
+    Uses a real throwaway git repository so containment is computed by git
+    rather than asserted. Nothing outside the temporary directory is touched.
+    """
+
+    def _git(self, *args):
+        subprocess.run(
+            ["git", "-C", self.root, *args],
+            check=True,
+            capture_output=True,
+            text=True,
+        )
+
+    def setUp(self):
+        self._tmp = tempfile.TemporaryDirectory()
+        self.root = os.path.realpath(self._tmp.name)
+        self._git("init", "-b", "master", ".")
+        self._git("config", "user.email", "[email protected]")
+        self._git("config", "user.name", "Test")
+        with open(os.path.join(self.root, "seed.txt"), "w") as fh:
+            fh.write("seed\n")
+        self._git("add", "seed.txt")
+        self._git("commit", "-m", "seed")
+
+        self.branch = "feat/issue-777-timeline"
+        self._git("checkout", "-b", self.branch)
+        with open(os.path.join(self.root, "feature.txt"), "w") as fh:
+            fh.write("feature\n")
+        self._git("add", "feature.txt")
+        self._git("commit", "-m", "feature")
+        self.head_sha = subprocess.run(
+            ["git", "-C", self.root, "rev-parse", "HEAD"],
+            capture_output=True, text=True, check=True,
+        ).stdout.strip()
+        self._git("checkout", "master")
+        self._git("merge", "--no-ff", "-m", "merge feature", self.branch)
+
+        self.worktree = os.path.join(self.root, "branches", "issue-777-timeline")
+        self._git("worktree", "add", self.worktree, self.branch)
+
+    def tearDown(self):
+        self._tmp.cleanup()
+
+    def _pr_index(self):
+        return wca.build_pr_index(
+            [
+                {
+                    "number": 849,
+                    "head": {"ref": self.branch, "sha": self.head_sha},
+                    "merged_at": "2026-07-24T01:00:00Z",
+                }
+            ]
+        )
+
+    def _audit_entry(self):
+        report = wca.audit_branches_directory(
+            self.root, pr_index=self._pr_index(), master_ref="master"
+        )
+        return next(wt for wt in report["worktrees"] if wt["path"] == self.worktree)
+
+    def _reconciler_entry(self):
+        return mcr.assess_local_worktree_cleanup(
+            pr_number=849,
+            head_branch=self.branch,
+            merged=True,
+            worktree_state=mcr.resolve_cleanup_worktree_state(
+                project_root=self.root,
+                head_branch=self.branch,
+                issue_number=777,
+                pr_head_sha=self.head_sha,
+                target_ref="master",
+            ),
+            active_lock=False,
+        )
+
+    def test_both_assessors_agree_the_worktree_is_safe(self):
+        audit_entry = self._audit_entry()
+        reconciler = self._reconciler_entry()
+
+        self.assertTrue(reconciler["safe_to_remove_worktree"], reconciler)
+        self.assertTrue(audit_entry["removable"], audit_entry)
+        self.assertEqual(audit_entry["pr_number"], reconciler["pr_number"])
+        self.assertEqual(audit_entry["merged_pr_cleanup"]["block_reasons"], [])
+        self.assertEqual(reconciler["block_reasons"], [])
+
+    def test_both_assessors_agree_a_dirty_worktree_is_unsafe(self):
+        with open(os.path.join(self.worktree, "feature.txt"), "a") as fh:
+            fh.write("local edit\n")
+
+        audit_entry = self._audit_entry()
+        reconciler = self._reconciler_entry()
+
+        self.assertFalse(audit_entry["removable"])
+        self.assertFalse(reconciler["safe_to_remove_worktree"])
+
+    def test_worktree_still_present_after_audit(self):
+        self._audit_entry()
+        self.assertTrue(os.path.isdir(self.worktree))
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_issue_871_durable_lock_head_refresh.py

@@ -0,0 +1,630 @@
+"""Durable linked-issue lock head refresh + merge-sync dead-session recovery (#871).
+
+``gitea_update_pr_branch_by_merge`` advances a PR's *remote* head but historically
+never advanced the linked durable issue lock's recorded head. After the owning
+session died the drifted lock became unrecoverable and no further synchronization
+was possible (PR #866 / issue #855).
+
+Two halves are covered:
+
+* the write-side refresh (``issue_lock_store.assess/apply_durable_lock_head_refresh``)
+  that records the new synced head under compare-and-swap with read-after-write; and
+* the read-side recovery relation (``issue_lock_recovery`` +
+  ``issue_lock_worktree.read_merge_sync_provenance``) that lets a dead-session lock
+  whose recorded head is a merge-sync *ancestor* of the live PR head be recovered —
+  and nothing else.
+"""
+
+from __future__ import annotations
+
+import os
+import subprocess
+import sys
+import tempfile
+import unittest
+from datetime import datetime, timedelta, timezone
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+import issue_lock_recovery  # noqa: E402
+import issue_lock_store  # noqa: E402
+import issue_lock_worktree  # noqa: E402
+
+ISSUE = 8710
+PR_NUMBER = 8711
+BRANCH = f"fix/issue-{ISSUE}-durable-lock-head-refresh"
+IDENTITY = "example-user"
+PROFILE = "example-author"
+OLD = "a" * 40
+NEW1 = "b" * 40
+NEW2 = "c" * 40
+BASE = "d" * 40
+REMOTE = "prgs"
+ORG = "ExampleOrg"
+REPO = "ExampleRepo"
+
+
+def dead_pid() -> int:
+    proc = subprocess.Popen([sys.executable, "-c", "pass"])
+    proc.wait()
+    return proc.pid
+
+
+def future_ts(hours: int = 4) -> str:
+    return (
+        (datetime.now(timezone.utc) + timedelta(hours=hours))
+        .isoformat()
+        .replace("+00:00", "Z")
+    )
+
+
+def _git(cwd, *args):
+    return subprocess.run(
+        ["git", "-C", cwd, *args],
+        capture_output=True,
+        text=True,
+        check=True,
+    )
+
+
+def _rev(cwd, ref="HEAD") -> str:
+    return _git(cwd, "rev-parse", ref).stdout.strip()
+
+
+def build_merge_sync_repo(tmp: str) -> dict:
+    """Build a repo where a feature branch was synced by merging master in.
+
+    Returns a dict with the prior (branch) head, the synced merge-commit head,
+    the master tip, plus a rebase-style linear descendant and an unrelated head.
+    """
+    _git(tmp, "init", "-q", "-b", "master")
+    _git(tmp, "config", "user.email", "[email protected]")
+    _git(tmp, "config", "user.name", "T")
+    Path(tmp, "base.txt").write_text("base\n")
+    _git(tmp, "add", "-A")
+    _git(tmp, "commit", "-q", "-m", "root")
+
+    # Feature branch cut from root, one commit — this is the PRIOR/recorded head.
+    _git(tmp, "checkout", "-q", "-b", BRANCH)
+    Path(tmp, "feature.txt").write_text("feature\n")
+    _git(tmp, "add", "-A")
+    _git(tmp, "commit", "-q", "-m", "feature work")
+    prior = _rev(tmp)
+
+    # Master advances (the base the sync will merge in).
+    _git(tmp, "checkout", "-q", "master")
+    Path(tmp, "base.txt").write_text("base\nmore\n")
+    _git(tmp, "add", "-A")
+    _git(tmp, "commit", "-q", "-m", "master advance")
+    master_tip = _rev(tmp)
+
+    # Sync: merge master INTO the feature branch → merge commit, first parent = prior.
+    _git(tmp, "checkout", "-q", BRANCH)
+    _git(tmp, "merge", "-q", "--no-ff", "-m", "Merge master into feature", "master")
+    synced = _rev(tmp)
+
+    # A plain linear descendant of prior (NOT a merge) — a rebase/extra-commit shape.
+    _git(tmp, "checkout", "-q", "-b", "linear-branch", prior)
+    Path(tmp, "extra.txt").write_text("extra\n")
+    _git(tmp, "add", "-A")
+    _git(tmp, "commit", "-q", "-m", "extra linear commit")
+    linear = _rev(tmp)
+
+    # An unrelated root (force-push / rewritten history shape).
+    unrelated_dir = tempfile.mkdtemp()
+    _git(unrelated_dir, "init", "-q", "-b", "x")
+    _git(unrelated_dir, "config", "user.email", "[email protected]")
+    _git(unrelated_dir, "config", "user.name", "T")
+    Path(unrelated_dir, "z.txt").write_text("z\n")
+    _git(unrelated_dir, "add", "-A")
+    _git(unrelated_dir, "commit", "-q", "-m", "unrelated")
+    unrelated = _rev(unrelated_dir)
+
+    # Leave the worktree checked out on the feature branch at the PRIOR head, as
+    # a dead author session that never advanced would have left it.
+    _git(tmp, "checkout", "-q", BRANCH)
+    _git(tmp, "reset", "-q", "--hard", prior)
+
+    return {
+        "prior": prior,
+        "master_tip": master_tip,
+        "synced": synced,
+        "linear": linear,
+        "unrelated": unrelated,
+    }
+
+
+# ─────────────────────────── write-side refresh ───────────────────────────
+
+
+class TestDurableLockHeadRefresh(unittest.TestCase):
+    def setUp(self):
+        self.lock_dir = tempfile.mkdtemp()
+        self.wt = tempfile.mkdtemp()
+        lock_data = {
+            "issue_number": ISSUE,
+            "branch_name": BRANCH,
+            "worktree_path": self.wt,
+            "remote": REMOTE,
+            "org": ORG,
+            "repo": REPO,
+            "claimant": {"username": IDENTITY, "profile": PROFILE},
+            "work_lease": {
+                "operation_type": issue_lock_store.AUTHOR_ISSUE_WORK_LEASE,
+                "issue_number": ISSUE,
+                "branch": BRANCH,
+                "worktree_path": self.wt,
+                "claimant": {"username": IDENTITY, "profile": PROFILE},
+                "expires_at": future_ts(),
+            },
+        }
+        issue_lock_store.bind_session_lock(lock_data, lock_dir=self.lock_dir)
+
+    def _apply(self, **over):
+        kw = dict(
+            remote=REMOTE, org=ORG, repo=REPO, issue_number=ISSUE,
+            branch_name=BRANCH, worktree_path=self.wt, pr_number=PR_NUMBER,
+            identity=IDENTITY, profile=PROFILE, current_pid=os.getpid(),
+            expected_old_head=OLD, new_head=NEW1, synced_at=future_ts(0),
+            base_head=BASE, lock_dir=self.lock_dir,
+        )
+        kw.update(over)
+        return issue_lock_store.apply_durable_lock_head_refresh(**kw)
+
+    def _load(self):
+        return issue_lock_store.load_issue_lock(
+            remote=REMOTE, org=ORG, repo=REPO, issue_number=ISSUE,
+            lock_dir=self.lock_dir,
+        )
+
+    def test_first_sync_updates_recorded_head(self):
+        """AC1: first base sync writes the resulting head to the durable lock."""
+        res = self._apply()
+        self.assertTrue(res["refreshed"], res["reasons"])
+        self.assertTrue(res["read_after_write_ok"])
+        self.assertEqual(self._load().get("synced_pr_head"), NEW1)
+
+    def test_second_sync_after_master_advance(self):
+        """AC2: a later master advance permits a second sanctioned sync."""
+        self.assertTrue(self._apply()["refreshed"])
+        res2 = self._apply(expected_old_head=NEW1, new_head=NEW2)
+        self.assertTrue(res2["refreshed"], res2["reasons"])
+        self.assertEqual(self._load().get("synced_pr_head"), NEW2)
+        history = self._load().get("branch_sync_history")
+        self.assertEqual(len(history), 2)
+        self.assertEqual(history[0]["last_synced_pr_head"], NEW1)
+        self.assertEqual(history[1]["prior_pr_head"], NEW1)
+
+    def test_cas_detects_concurrent_head_change(self):
+        """AC6: CAS refuses when the recorded synced head is not the old head."""
+        self.assertTrue(self._apply()["refreshed"])  # recorded head now NEW1
+        # A second sync claiming the old head is still OLD must fail closed.
+        res = self._apply(expected_old_head=OLD, new_head=NEW2)
+        self.assertFalse(res["refreshed"])
+        self.assertTrue(any("CAS" in r or "concurrent" in r for r in res["reasons"]))
+        self.assertEqual(self._load().get("synced_pr_head"), NEW1)
+
+    def test_wrong_issue_fails_closed(self):
+        res = self._apply(issue_number=999999)
+        self.assertFalse(res["refreshed"])
+
+    def test_wrong_branch_fails_closed(self):
+        res = self._apply(branch_name="fix/issue-8710-wrong")
+        self.assertFalse(res["refreshed"])
+
+    def test_wrong_repo_fails_closed(self):
+        res = self._apply(repo="OtherRepo")
+        self.assertFalse(res["refreshed"])
+
+    def test_wrong_identity_fails_closed(self):
+        res = self._apply(identity="intruder")
+        self.assertFalse(res["refreshed"])
+
+    def test_wrong_profile_fails_closed(self):
+        res = self._apply(profile="prgs-reviewer")
+        self.assertFalse(res["refreshed"])
+
+    def test_foreign_session_fails_closed(self):
+        """A refresh is not a recovery: the current process must own the lock."""
+        path = issue_lock_store.lock_file_path(
+            remote=REMOTE, org=ORG, repo=REPO, issue_number=ISSUE,
+            lock_dir=self.lock_dir,
+        )
+        rec = issue_lock_store.read_lock_file(path)
+        rec["session_pid"] = dead_pid()
+        rec["pid"] = rec["session_pid"]
+        issue_lock_store.save_lock_file(path, rec)
+        res = self._apply()
+        self.assertFalse(res["refreshed"])
+        self.assertTrue(any("current session" in r or "live owner" in r for r in res["reasons"]))
+
+    def test_new_equals_old_fails_closed(self):
+        res = self._apply(expected_old_head=OLD, new_head=OLD)
+        self.assertFalse(res["refreshed"])
+
+    def test_non_full_sha_fails_closed(self):
+        self.assertFalse(self._apply(new_head="deadbeef")["refreshed"])
+        self.assertFalse(self._apply(expected_old_head="xyz")["refreshed"])
+
+    def test_no_lock_fails_closed(self):
+        assessment = issue_lock_store.assess_durable_lock_head_refresh(
+            None, remote=REMOTE, org=ORG, repo=REPO, issue_number=ISSUE,
+            branch_name=BRANCH, worktree_path=self.wt, pr_number=PR_NUMBER,
+            identity=IDENTITY, profile=PROFILE, current_pid=os.getpid(),
+            expected_old_head=OLD, new_head=NEW1,
+        )
+        self.assertFalse(assessment["allowed"])
+
+
+# ─────────────────────── merge-sync provenance (real git) ───────────────────
+
+
+class TestMergeSyncProvenanceObservation(unittest.TestCase):
+    def setUp(self):
+        self.tmp = tempfile.mkdtemp()
+        self.shas = build_merge_sync_repo(self.tmp)
+
+    def test_merge_sync_is_recognized(self):
+        obs = issue_lock_worktree.read_merge_sync_provenance(
+            self.tmp, prior_head_sha=self.shas["prior"],
+            synced_head_sha=self.shas["synced"],
+        )
+        self.assertTrue(obs["is_merge_sync"], obs["reasons"])
+        self.assertTrue(obs["prior_is_ancestor"])
+        self.assertTrue(obs["synced_is_merge"])
+        self.assertTrue(obs["first_parent_reaches_prior"])
+
+    def test_linear_descendant_is_not_a_merge_sync(self):
+        """A plain non-merge descendant (rebase/extra commit) is not a sync."""
+        obs = issue_lock_worktree.read_merge_sync_provenance(
+            self.tmp, prior_head_sha=self.shas["prior"],
+            synced_head_sha=self.shas["linear"],
+        )
+        self.assertTrue(obs["probe_ok"])
+        self.assertFalse(obs["is_merge_sync"])
+        self.assertFalse(obs["synced_is_merge"])
+
+    def test_unrelated_history_fails_closed(self):
+        """A rewritten/force-pushed head where prior is unreachable fails closed."""
+        obs = issue_lock_worktree.read_merge_sync_provenance(
+            self.tmp, prior_head_sha=self.shas["prior"],
+            synced_head_sha=self.shas["unrelated"],
+        )
+        self.assertFalse(obs["is_merge_sync"])
+
+    def test_missing_args_fail_closed(self):
+        obs = issue_lock_worktree.read_merge_sync_provenance(
+            self.tmp, prior_head_sha=None, synced_head_sha=self.shas["synced"],
+        )
+        self.assertFalse(obs["is_merge_sync"])
+
+
+# ──────────────────── merge-sync dead-session recovery ──────────────────────
+
+
+def make_dead_lock(worktree, **over):
+    pid = dead_pid()
+    lock = {
+        "issue_number": ISSUE,
+        "branch_name": BRANCH,
+        "worktree_path": worktree,
+        "remote": REMOTE,
+        "org": ORG,
+        "repo": REPO,
+        "session_pid": pid,
+        "pid": pid,
+        "claimant": {"username": IDENTITY, "profile": PROFILE},
+        "work_lease": {
+            "operation_type": issue_lock_store.AUTHOR_ISSUE_WORK_LEASE,
+            "issue_number": ISSUE,
+            "branch": BRANCH,
+            "worktree_path": worktree,
+            "claimant": {"username": IDENTITY, "profile": PROFILE},
+            "expires_at": future_ts(),
+        },
+    }
+    lock.update(over)
+    return lock
+
+
+def sync_prov(prior, synced, **over):
+    d = {
+        "prior_head_sha": prior,
+        "synced_head_sha": synced,
+        "probe_ok": True,
+        "prior_present": True,
+        "synced_present": True,
+        "prior_is_ancestor": True,
+        "synced_is_merge": True,
+        "first_parent_reaches_prior": True,
+        "is_merge_sync": True,
+        "first_parent_sha": prior,
+        "parent_count": 2,
+        "proof": f"{synced} merged base into branch above {prior}",
+        "reasons": [],
+    }
+    d.update(over)
+    return d
+
+
+class TestMergeSyncRecovery(unittest.TestCase):
+    def setUp(self):
+        self.tmp = tempfile.mkdtemp()
+        self.shas = build_merge_sync_repo(self.tmp)
+        self.prior = self.shas["prior"]
+        self.synced = self.shas["synced"]
+
+    def _assess(self, **over):
+        lock = over.pop("_lock", None) or make_dead_lock(self.tmp)
+        kw = dict(
+            issue_number=ISSUE, branch_name=BRANCH, worktree_path=self.tmp,
+            remote=REMOTE, org=ORG, repo=REPO, identity=IDENTITY, profile=PROFILE,
+            current_branch=BRANCH, porcelain_status="",
+            head_sha=self.prior, remote_head_sha=self.synced,
+            pr_head_sha=self.synced, pr_number=PR_NUMBER,
+            competing_live_locks=[], candidate_branches=[BRANCH],
+            current_pid=os.getpid(),
+            remote_branch_exists=True,
+            sync_provenance=sync_prov(self.prior, self.synced),
+        )
+        kw.update(over)
+        return issue_lock_recovery.assess_dead_session_lock_recovery(lock, **kw)
+
+    def test_merge_sync_drift_is_recoverable(self):
+        """AC3/AC4: dead session, recorded head is a merge-sync ancestor of PR head."""
+        res = self._assess()
+        self.assertEqual(res["outcome"], issue_lock_recovery.RECOVERY_SANCTIONED, res["reasons"])
+        self.assertEqual(
+            res["evidence"]["head_relation"],
+            issue_lock_recovery.HEAD_RELATION_REMOTE_MERGE_SYNCED,
+        )
+        self.assertEqual(res["evidence"]["accepted_head"], self.synced)
+
+    def test_missing_provenance_fails_closed(self):
+        """No server-derived provenance → cannot accept a remote ahead of local."""
+        res = self._assess(sync_provenance=None)
+        self.assertEqual(res["outcome"], issue_lock_recovery.REFUSED)
+
+    def test_non_ancestor_recorded_head_fails_closed(self):
+        """AC7: provenance that does not prove ancestry is rejected."""
+        res = self._assess(
+            sync_provenance=sync_prov(
+                self.prior, self.synced, prior_is_ancestor=False, is_merge_sync=False,
+                reasons=["prior head is not an ancestor"],
+            )
+        )
+        self.assertEqual(res["outcome"], issue_lock_recovery.REFUSED)
+
+    def test_force_pushed_history_fails_closed(self):
+        """AC8: a rewritten head (not a merge sync) stays protected."""
+        res = self._assess(
+            sync_provenance=sync_prov(
+                self.prior, self.synced, is_merge_sync=False, synced_is_merge=False,
+                reasons=["not a merge-based sync"],
+            )
+        )
+        self.assertEqual(res["outcome"], issue_lock_recovery.REFUSED)
+
+    def test_provenance_for_other_commits_fails_closed(self):
+        """Provenance whose endpoints differ from the heads under assessment is rejected."""
+        res = self._assess(
+            sync_provenance=sync_prov("f" * 40, self.synced),
+        )
+        self.assertEqual(res["outcome"], issue_lock_recovery.REFUSED)
+
+    def test_dirty_worktree_fails_closed(self):
+        """AC11: dirty worktrees remain protected."""
+        res = self._assess(porcelain_status=" M feature.txt\n")
+        self.assertEqual(res["outcome"], issue_lock_recovery.REFUSED)
+
+    def test_live_owner_fails_closed(self):
+        """AC10: a live recorded owner is not a dead-session recovery."""
+        lock = make_dead_lock(self.tmp, session_pid=os.getpid(), pid=os.getpid())
+        res = self._assess(_lock=lock)
+        self.assertEqual(res["outcome"], issue_lock_recovery.REFUSED)
+
+    def test_competing_claimant_fails_closed(self):
+        """AC13: a competing live lock blocks recovery."""
+        res = self._assess(
+            competing_live_locks=[{
+                "issue_number": ISSUE, "branch_name": BRANCH,
+                "worktree_path": "/some/other/wt", "pid": os.getpid(),
+            }]
+        )
+        self.assertEqual(res["outcome"], issue_lock_recovery.REFUSED)
+
+    def test_wrong_branch_fails_closed(self):
+        """AC9: worktree on a different branch fails closed."""
+        res = self._assess(current_branch="fix/issue-8710-other")
+        self.assertEqual(res["outcome"], issue_lock_recovery.REFUSED)
+
+    def test_wrong_identity_fails_closed(self):
+        res = self._assess(identity="intruder")
+        self.assertEqual(res["outcome"], issue_lock_recovery.REFUSED)
+
+    def test_pr_head_mismatch_fails_closed(self):
+        """The open PR must sit at the synced remote head."""
+        res = self._assess(pr_head_sha="e" * 40)
+        self.assertEqual(res["outcome"], issue_lock_recovery.REFUSED)
+
+    def test_owning_pr_evidence_for_merge_sync(self):
+        res = self._assess()
+        ev = issue_lock_recovery.owning_pr_recovery_evidence(res)
+        self.assertIsNotNone(ev)
+        self.assertEqual(ev["pr_number"], PR_NUMBER)
+        self.assertEqual(ev["head_sha"], self.synced)
+        self.assertEqual(
+            ev["head_relation"],
+            issue_lock_recovery.HEAD_RELATION_REMOTE_MERGE_SYNCED,
+        )
+
+    def test_recovered_owning_pr_from_persisted_record(self):
+        res = self._assess()
+        record = issue_lock_recovery.build_recovery_record(res, recovered_at=future_ts(0))
+        lock = {"issue_number": ISSUE, "branch_name": BRANCH,
+                "dead_session_recovery": record}
+        rebuilt = issue_lock_recovery.recovered_owning_pr_from_lock(lock)
+        self.assertIsNotNone(rebuilt)
+        self.assertEqual(rebuilt["head_sha"], self.synced)
+        self.assertEqual(
+            rebuilt["head_relation"],
+            issue_lock_recovery.HEAD_RELATION_REMOTE_MERGE_SYNCED,
+        )
+
+
+class TestExistingRelationsUnchanged(unittest.TestCase):
+    """AC14/AC15: equal-head recovery still works; merge-sync did not weaken it."""
+
+    def setUp(self):
+        self.tmp = tempfile.mkdtemp()
+        self.shas = build_merge_sync_repo(self.tmp)
+
+    def test_equal_head_recovery_still_sanctioned(self):
+        # Worktree at prior head; remote also at prior head → the #753 equal case.
+        prior = self.shas["prior"]
+        lock = make_dead_lock(self.tmp)
+        res = issue_lock_recovery.assess_dead_session_lock_recovery(
+            lock, issue_number=ISSUE, branch_name=BRANCH, worktree_path=self.tmp,
+            remote=REMOTE, org=ORG, repo=REPO, identity=IDENTITY, profile=PROFILE,
+            current_branch=BRANCH, porcelain_status="",
+            head_sha=prior, remote_head_sha=prior,
+            pr_head_sha=prior, pr_number=PR_NUMBER,
+            competing_live_locks=[], candidate_branches=[BRANCH],
+            current_pid=os.getpid(), remote_branch_exists=True,
+        )
+        self.assertEqual(res["outcome"], issue_lock_recovery.RECOVERY_SANCTIONED, res["reasons"])
+        self.assertEqual(
+            res["evidence"]["head_relation"], issue_lock_recovery.HEAD_RELATION_EQUAL,
+        )
+
+
+class TestUpdatePrWrapperPartialFailure(unittest.TestCase):
+    """AC5/AC16: the tool advances the remote head then refreshes the durable lock.
+
+    When the durable refresh fails after the remote advance, the tool must report a
+    partial lifecycle failure and NOT a fully successful synchronization. Exact PR-
+    head / base-head pinning is preserved (delegated to the real preflight, stubbed
+    here only to isolate the post-update lifecycle branch).
+    """
+
+    def setUp(self):
+        import gitea_mcp_server as gms  # noqa: E402
+        self.gms = gms
+        self._orig = {}
+
+        def _patch(name, value):
+            self._orig[name] = getattr(gms, name)
+            setattr(gms, name, value)
+
+        _patch("get_profile", lambda *a, **k: {
+            "allowed_operations": ["gitea.branch.push"],
+            "forbidden_operations": [],
+            "profile_name": "prgs-author",
+        })
+        _patch("_role_kind", lambda *a, **k: "author")
+        _patch("_profile_operation_gate", lambda *a, **k: None)
+        _patch("_permission_block_report", lambda *a, **k: {})
+        _patch("_resolve", lambda *a, **k: ("gitea.prgs.cc", ORG, REPO))
+        _patch("_verify_role_mutation_workspace", lambda *a, **k: None)
+        _patch("_get_workspace_porcelain", lambda *a, **k: "")
+        _patch("_canonical_local_git_root", lambda *a, **k: "/x")
+        _patch("_master_parity_block", lambda *a, **k: None)
+        _patch("_auth", lambda *a, **k: {"token": "x"})
+        _patch("repo_api_url", lambda *a, **k: "http://api")
+        _patch("_redact", lambda s: s)
+        _patch("_work_lease_claimant", lambda *a, **k: {
+            "username": IDENTITY, "profile": PROFILE,
+        })
+        _patch("_prove_author_ownership_for_pr", lambda *a, **k: {
+            "has_author_lock": True, "matched_issue": ISSUE,
+            "matched_via": "branch", "linked_issues": [ISSUE],
+            "recovered_owning_pr": None, "reasons": [],
+        })
+
+        # Real preflight is unit-tested elsewhere; stub it to isolate the
+        # post-update durable-lock lifecycle branch under test.
+        orig_pf = gms.pr_sync_status.assess_update_pr_branch_preflight
+        self._orig_pf = orig_pf
+        gms.pr_sync_status.assess_update_pr_branch_preflight = (
+            lambda *a, **k: {"mutation_allowed": True, "reasons": [], "performed": False}
+        )
+
+        # Sequence the two GET /pulls calls: OLD before update, NEW after.
+        self._pull_calls = {"n": 0}
+
+        def fake_api_request(method, url, auth, *a, **k):
+            m = method.upper()
+            if m == "GET" and url.endswith(f"/pulls/{PR_NUMBER}"):
+                self._pull_calls["n"] += 1
+                head = OLD if self._pull_calls["n"] == 1 else NEW1
+                return {
+                    "state": "open",
+                    "head": {"sha": head, "ref": BRANCH},
+                    "base": {"sha": BASE, "ref": "master"},
+                    "mergeable": True, "title": "t", "body": "b",
+                }
+            if m == "GET" and "/branches/" in url:
+                return {"commit": {"id": BASE}}
+            if m == "POST" and "/update" in url:
+                return {}
+            return {}
+
+        _patch("api_request", fake_api_request)
+
+    def tearDown(self):
+        for name, value in self._orig.items():
+            setattr(self.gms, name, value)
+        self.gms.pr_sync_status.assess_update_pr_branch_preflight = self._orig_pf
+
+    def _run(self):
+        return self.gms.gitea_update_pr_branch_by_merge(
+            pr_number=PR_NUMBER,
+            expected_pr_head_sha=OLD,
+            expected_base_head_sha=BASE,
+            remote=REMOTE,
+            worktree_path="/tmp/branches/wt-871",
+        )
+
+    def test_partial_failure_when_refresh_fails(self):
+        self._orig["apply_durable_lock_head_refresh"] = (
+            self.gms.issue_lock_store.apply_durable_lock_head_refresh
+        )
+        self.gms.issue_lock_store.apply_durable_lock_head_refresh = (
+            lambda **k: {"refreshed": False, "reasons": ["forced refresh failure"]}
+        )
+        try:
+            res = self._run()
+        finally:
+            self.gms.issue_lock_store.apply_durable_lock_head_refresh = (
+                self._orig["apply_durable_lock_head_refresh"]
+            )
+        self.assertTrue(res["performed"])
+        self.assertEqual(res["new_pr_head_sha"], NEW1)
+        self.assertFalse(res["success"])
+        self.assertTrue(res["partial_lifecycle_failure"])
+        self.assertFalse(res["durable_lock_refreshed"])
+
+    def test_full_success_when_refresh_succeeds(self):
+        self._orig["apply_durable_lock_head_refresh"] = (
+            self.gms.issue_lock_store.apply_durable_lock_head_refresh
+        )
+        self.gms.issue_lock_store.apply_durable_lock_head_refresh = (
+            lambda **k: {"refreshed": True, "read_after_write_ok": True,
+                         "new_head": NEW1, "reasons": ["ok"]}
+        )
+        try:
+            res = self._run()
+        finally:
+            self.gms.issue_lock_store.apply_durable_lock_head_refresh = (
+                self._orig["apply_durable_lock_head_refresh"]
+            )
+        self.assertTrue(res["success"])
+        self.assertTrue(res["performed"])
+        self.assertTrue(res["durable_lock_refreshed"])
+        self.assertTrue(res["fully_synchronized"])
+        self.assertEqual(res["new_pr_head_sha"], NEW1)
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_issue_lock_store.py

@@ -24,6 +24,8 @@ def _lease(expires_at: str) -> dict:
 
 
 def _lock_record(**overrides) -> dict:
+    # #860: live locks require a usable session pid; PID-less records are never
+    # classified live merely because expiry/heartbeat fields are present.
     record = {
         "issue_number": 420,
         "branch_name": "feat/issue-420-server-code-parity",
@@ -31,6 +33,8 @@ def _lock_record(**overrides) -> dict:
         "org": "Scaled-Tech-Consulting",
         "repo": "Gitea-Tools",
         "worktree_path": "/tmp/wt-420",
+        "session_pid": os.getpid(),
+        "pid": os.getpid(),
         "work_lease": _lease("2999-01-01T00:00:00Z"),
     }
     record.update(overrides)
@@ -88,6 +92,8 @@ class TestIssueLockStore(unittest.TestCase):
         existing = _lock_record(
             branch_name="feat/issue-420-other",
             worktree_path="/tmp/other",
+            session_pid=os.getpid(),
+            pid=os.getpid(),
             work_lease=_lease("2999-01-01T00:00:00Z"),
         )
         path = ils.lock_file_path(

tests/test_mcp_restart_governance_docs.py

@@ -0,0 +1,107 @@
+"""Documentation acceptance for the MCP restart governance ADR (#656).
+
+Enforces issue #656 acceptance criteria:
+
+* AC1 — policy document exists with an authorization matrix and the recorded
+  v1 decision (controller approval + automated safety gates).
+* AC2 — restart is stated as a last resort with enumerated narrower recoveries.
+* AC3 — a unilateral LLM full restart with affected sessions is forbidden.
+* AC4 — break-glass conditions are listed.
+* AC5 — the ADR is linked to #655, #652, #653, #630, #642, and is cross-linked
+  from the safety model and the web-console deployment boundary docs.
+"""
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parent.parent
+ADR = REPO_ROOT / "docs" / "architecture" / "mcp-restart-governance.md"
+ADR_BASENAME = "mcp-restart-governance.md"
+
+CROSS_LINK_DOCS = (
+    REPO_ROOT / "docs" / "safety-model.md",
+    REPO_ROOT / "docs" / "webui-deployment.md",
+)
+
+LINKED_ISSUES = ("#655", "#652", "#653", "#630", "#642")
+POLICY_IDS = ("RG-01", "RG-02", "RG-03", "RG-04", "RG-05", "RG-06", "RG-07", "RG-08")
+
+
+def _read(path: Path) -> str:
+    assert path.is_file(), f"missing {path.relative_to(REPO_ROOT)}"
+    return path.read_text(encoding="utf-8")
+
+
+def test_ac1_adr_exists_with_matrix_and_v1_decision():
+    text = _read(ADR)
+    lower = text.lower()
+    assert text.lstrip().startswith("#"), "ADR lacks a title"
+    assert "#656" in text
+    assert "authorization matrix" in lower
+    # The matrix is a real table with the worker and privileged roles.
+    for role in ("author", "reviewer", "merger", "reconciler", "controller",
+                 "operator", "admin"):
+        assert role in lower, f"authorization matrix missing role {role!r}"
+    # Recorded v1 decision.
+    assert "restart-governance/v1" in text
+    assert "controller approval" in lower and "automated safety gates" in lower
+
+
+def test_ac2_restart_is_last_resort_with_narrower_recoveries():
+    text = _read(ADR)
+    lower = text.lower()
+    assert "last resort" in lower
+    # Enumerated narrower recoveries precede full restart on the ladder.
+    for rung in ("reconnect", "rebind", "scoped restart", "full restart",
+                 "host"):
+        assert rung in lower, f"recovery ladder missing rung {rung!r}"
+
+
+def test_ac3_forbids_unilateral_llm_full_restart_with_affected_sessions():
+    text = _read(ADR)
+    lower = text.lower()
+    assert "forbidden" in lower
+    assert "llm" in lower and "restart" in lower
+    assert "unilateral" in lower
+    # A worker role must not perform or authorize full/host restart.
+    assert "must not" in lower
+
+
+def test_ac4_break_glass_conditions_listed():
+    text = _read(ADR)
+    lower = text.lower()
+    assert "break-glass" in lower
+    assert "incident" in lower
+    assert "audit" in lower
+
+
+def test_ac5_adr_links_issue_lineage():
+    text = _read(ADR)
+    for issue in LINKED_ISSUES:
+        assert issue in text, f"ADR must link issue {issue}"
+
+
+def test_ac5_safety_model_and_deployment_cross_link_adr():
+    for path in CROSS_LINK_DOCS:
+        text = _read(path)
+        assert ADR_BASENAME in text, (
+            f"{path.relative_to(REPO_ROOT)} must cross-link {ADR_BASENAME} "
+            f"(issue #656 acceptance criterion 5)"
+        )
+
+
+def test_policy_ids_present_for_enforcement_code():
+    text = _read(ADR)
+    for pid in POLICY_IDS:
+        assert pid in text, f"policy id {pid} missing from ADR"
+
+
+def test_failure_behavior_denies_on_ambiguity():
+    text = _read(ADR)
+    lower = text.lower()
+    assert "ambiguous" in lower and "deny" in lower
+
+
+def test_cross_links_do_not_embed_secrets():
+    for path in (ADR,) + CROSS_LINK_DOCS:
+        text = _read(path)
+        for marker in ("ghp_", "BEGIN PRIVATE KEY", "Authorization: Bearer"):
+            assert marker not in text, f"{path} contains {marker!r}"

tests/test_mcp_restart_paths.py

@@ -0,0 +1,146 @@
+"""Tests for the MCP restart-path inventory and guards (#657).
+
+Covers:
+* the registry is well-formed and every path is classified;
+* unknown restart attempts fail closed (AC "fail closed on unknown restart");
+* the previously-unguarded full-restart primitives stay guarded/absent
+  against the real source tree (AC "tests for at least one previously
+  unguarded path");
+* pkill of the daemon is still classified as contamination (#630, AC3);
+* the inventory doc and module stay in lock-step.
+"""
+
+import os
+import tempfile
+import unittest
+from pathlib import Path
+
+import mcp_restart_paths as rp
+import runtime_recovery_guard
+
+REPO_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+DOC_PATH = os.path.join(REPO_ROOT, "docs", "mcp-restart-path-inventory.md")
+
+
+class TestRegistryWellformed(unittest.TestCase):
+    def test_registry_is_wellformed(self):
+        # Must not raise.
+        rp.assert_registry_wellformed()
+
+    def test_every_path_has_valid_classification(self):
+        for path in rp.iter_restart_paths():
+            self.assertIn(path.classification, rp.VALID_CLASSIFICATIONS)
+            self.assertTrue(path.guard.strip(), path.path_id)
+            self.assertTrue(path.references, path.path_id)
+            self.assertTrue(path.locations, path.path_id)
+
+    def test_ids_are_unique(self):
+        ids = [p.path_id for p in rp.iter_restart_paths()]
+        self.assertEqual(len(ids), len(set(ids)))
+
+    def test_covers_every_classification(self):
+        present = {p.classification for p in rp.iter_restart_paths()}
+        self.assertEqual(present, set(rp.VALID_CLASSIFICATIONS))
+
+
+class TestUnknownAttemptFailsClosed(unittest.TestCase):
+    def test_unknown_path_raises(self):
+        with self.assertRaises(rp.UnknownRestartPathError):
+            rp.assert_restart_attempt_registered("totally_novel_restart_hack")
+
+    def test_get_unknown_raises(self):
+        with self.assertRaises(rp.UnknownRestartPathError):
+            rp.get_restart_path("nope")
+
+    def test_registered_attempt_returns_path(self):
+        path = rp.assert_restart_attempt_registered("manual_daemon_kill")
+        self.assertEqual(path.classification, rp.CLASS_FORBIDDEN)
+
+
+class TestDaemonNeverSelfReplaces(unittest.TestCase):
+    """Previously-unguarded full-restart primitive: daemon self-replacement."""
+
+    def test_no_self_replacement_in_source(self):
+        # The live daemon modules must contain no os.execv/os.kill/os._exit
+        # self-restart call. Must not raise.
+        rp.assert_no_daemon_self_replacement(REPO_ROOT)
+
+    def test_scanner_flags_injected_violation(self):
+        # Guard the guard: prove the scanner catches a real self-replace call.
+        with tempfile.TemporaryDirectory() as tmp:
+            bad = Path(tmp) / "gitea_mcp_server.py"
+            bad.write_text(
+                "import os\n"
+                "def restart():\n"
+                "    os.execv('/usr/bin/python', ['python'])\n",
+                encoding="utf-8",
+            )
+            found = rp.scan_daemon_self_replacement(tmp)
+            self.assertTrue(found)
+            with self.assertRaises(AssertionError):
+                rp.assert_no_daemon_self_replacement(tmp)
+
+    def test_scanner_ignores_comment_and_docstring_mentions(self):
+        with tempfile.TemporaryDirectory() as tmp:
+            ok = Path(tmp) / "gitea_mcp_server.py"
+            ok.write_text(
+                "import os\n"
+                "# NOT os.execv() to re-point the interpreter here.\n"
+                '"""Never calls os._exit to restart."""\n'
+                "value = 1\n",
+                encoding="utf-8",
+            )
+            self.assertEqual(rp.scan_daemon_self_replacement(tmp), [])
+
+
+class TestLegacyAutoRestartHelperRemoved(unittest.TestCase):
+    """Previously-unguarded full-restart path: _trigger_mcp_auto_restart."""
+
+    def test_helper_absent_in_source(self):
+        # Must not raise: helper was removed in #685.
+        rp.assert_auto_restart_helper_absent(REPO_ROOT)
+
+    def test_scanner_flags_reintroduced_helper(self):
+        with tempfile.TemporaryDirectory() as tmp:
+            bad = Path(tmp) / "mcp_server.py"
+            bad.write_text(
+                "def _trigger_mcp_auto_restart():\n    return True\n",
+                encoding="utf-8",
+            )
+            with self.assertRaises(AssertionError):
+                rp.assert_auto_restart_helper_absent(tmp)
+
+
+class TestPkillStaysForbidden(unittest.TestCase):
+    """AC3: pkill of the daemon remains forbidden/contaminating (#630)."""
+
+    def test_manual_daemon_kill_registered_as_forbidden(self):
+        path = rp.get_restart_path("manual_daemon_kill")
+        self.assertEqual(path.classification, rp.CLASS_FORBIDDEN)
+
+    def test_pkill_classified_as_contamination(self):
+        assessment = runtime_recovery_guard.assess_recovery_command(
+            "pkill -f mcp_server.py"
+        )
+        self.assertTrue(assessment["contaminated"])
+
+    def test_read_only_probe_not_contamination(self):
+        assessment = runtime_recovery_guard.assess_recovery_command(
+            "ps aux | grep mcp_server"
+        )
+        self.assertFalse(assessment["contaminated"])
+
+
+class TestInventoryDocInSync(unittest.TestCase):
+    def test_doc_exists(self):
+        self.assertTrue(os.path.exists(DOC_PATH), DOC_PATH)
+
+    def test_doc_mentions_every_path_id(self):
+        with open(DOC_PATH, encoding="utf-8") as handle:
+            doc = handle.read()
+        for path in rp.iter_restart_paths():
+            self.assertIn(path.path_id, doc, f"doc missing {path.path_id}")
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_pr_ownership_issue_pr_mismatch.py

@@ -37,6 +37,7 @@ def _live_lock(
         "operation_type": issue_lock_store.AUTHOR_ISSUE_WORK_LEASE,
         "acquired_at": now.isoformat(),
         "expires_at": (now + timedelta(hours=2)).isoformat(),
+        "session_pid": os.getpid(),
         "owner_pid": os.getpid(),
         "status": "active",
     }
@@ -177,11 +178,24 @@ class TestAuthorOwnershipIssuePrMismatch(unittest.TestCase):
         self.assertFalse(result["proven"], result)
         self.assertTrue(any("branch" in r for r in result["reasons"]))
 
-    def test_no_lock_fail_closed(self):
+    def test_pidless_durable_lock_rejected(self):
+        """A lock without any PID identity must be classified as malformed/non-live and fail closed."""
+        lock = _live_lock(issue_number=727)
+        lock.pop("session_pid", None)
+        lock.pop("owner_pid", None)
+        lock.pop("pid", None)
+        path = issue_lock_store.lock_file_path(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            issue_number=727,
+            lock_dir=self.lock_dir,
+        )
+        issue_lock_store.save_lock_file(path, lock)
         result = mcp._prove_author_ownership_for_pr(
             pr_number=728,
             pr_title="feat: pr sync",
-            pr_body="Closes #727",
+            pr_body="Fixes #727",
             source_branch="feat/issue-727-pr-sync-status",
             remote="prgs",
             host=None,

tests/test_pr_work_lease.py

@@ -19,6 +19,7 @@ from pr_work_lease import (  # noqa: E402
     assess_reviewer_mutation_blocked,
     assess_reviewer_stale_head_final_report,
     format_conflict_fix_lease_body,
+    find_active_conflict_fix_lease,
     parse_conflict_fix_lease_comment,
     parse_reviewer_lease_comment,
 )
@@ -203,5 +204,157 @@ class TestFormatLease(unittest.TestCase):
         self.assertEqual(parsed["pr_number"], 376)
 
 
+class TestConflictFixLeaseLifecycle(unittest.TestCase):
+    def test_claim_followed_by_matching_release(self):
+        claim_body = _conflict_fix_body(phase="claimed", worktree="branches/fix-376")
+        expires = (NOW + timedelta(minutes=60)).isoformat().replace("+00:00", "Z")
+        release_body = "\n".join([
+            CONFLICT_FIX_LEASE_MARKER,
+            "pr: #376",
+            "branch: feat/fix-376",
+            "worktree: branches/fix-376",
+            "profile: prgs-author",
+            "phase: released",
+            f"head_before: {HEAD_A}",
+            f"head_after: {HEAD_B}",
+            f"expires_at: {expires}",
+        ])
+        comments = [{"body": claim_body}, {"body": release_body}]
+        lease = find_active_conflict_fix_lease(comments, pr_number=376, now=NOW)
+        self.assertIsNone(lease)
+
+    def test_expired_claim_without_release(self):
+        past_expires = (NOW - timedelta(minutes=10)).isoformat().replace("+00:00", "Z")
+        claim_body = "\n".join([
+            CONFLICT_FIX_LEASE_MARKER,
+            "pr: #376",
+            "phase: claimed",
+            f"head_before: {HEAD_A}",
+            f"expires_at: {past_expires}",
+            "profile: prgs-author",
+        ])
+        comments = [{"body": claim_body}]
+        lease = find_active_conflict_fix_lease(comments, pr_number=376, now=NOW)
+        self.assertIsNone(lease)
+
+    def test_mismatched_release_different_head(self):
+        claim_body = _conflict_fix_body(phase="claimed", worktree="branches/fix-376")
+        expires = (NOW + timedelta(minutes=60)).isoformat().replace("+00:00", "Z")
+        release_body = "\n".join([
+            CONFLICT_FIX_LEASE_MARKER,
+            "pr: #376",
+            "profile: prgs-author",
+            "phase: released",
+            f"head_before: {HEAD_B}",
+            f"expires_at: {expires}",
+        ])
+        comments = [{"body": claim_body}, {"body": release_body}]
+        lease = find_active_conflict_fix_lease(comments, pr_number=376, now=NOW)
+        self.assertIsNotNone(lease)
+        self.assertEqual(lease["phase"], "claimed")
+
+    def test_mismatched_release_different_branch(self):
+        claim_body = "\n".join([
+            CONFLICT_FIX_LEASE_MARKER,
+            "pr: #376",
+            "branch: feat/branch-A",
+            "phase: claimed",
+            f"head_before: {HEAD_A}",
+            f"expires_at: {(NOW + timedelta(minutes=60)).isoformat().replace('+00:00', 'Z')}",
+            "profile: prgs-author",
+        ])
+        release_body = "\n".join([
+            CONFLICT_FIX_LEASE_MARKER,
+            "pr: #376",
+            "branch: feat/branch-B",
+            "phase: released",
+            f"head_before: {HEAD_A}",
+            f"expires_at: {(NOW + timedelta(minutes=60)).isoformat().replace('+00:00', 'Z')}",
+            "profile: prgs-author",
+        ])
+        comments = [{"body": claim_body}, {"body": release_body}]
+        lease = find_active_conflict_fix_lease(comments, pr_number=376, now=NOW)
+        self.assertIsNotNone(lease)
+        self.assertEqual(lease["phase"], "claimed")
+
+    def test_release_followed_by_newer_claim(self):
+        claim_1 = _conflict_fix_body(phase="claimed", worktree="branches/fix-376")
+        expires = (NOW + timedelta(minutes=60)).isoformat().replace("+00:00", "Z")
+        release_1 = "\n".join([
+            CONFLICT_FIX_LEASE_MARKER,
+            "pr: #376",
+            "profile: prgs-author",
+            "phase: released",
+            f"head_before: {HEAD_A}",
+            f"head_after: {HEAD_B}",
+            f"expires_at: {expires}",
+        ])
+        claim_2 = "\n".join([
+            CONFLICT_FIX_LEASE_MARKER,
+            "pr: #376",
+            "profile: prgs-author",
+            "phase: claimed",
+            f"head_before: {HEAD_B}",
+            f"expires_at: {expires}",
+        ])
+        comments = [{"body": claim_1}, {"body": release_1}, {"body": claim_2}]
+        lease = find_active_conflict_fix_lease(comments, pr_number=376, now=NOW)
+        self.assertIsNotNone(lease)
+        self.assertEqual(lease["head_before"], HEAD_B)
+
+    def test_malformed_or_ambiguous_markers(self):
+        malformed_release = "\n".join([
+            CONFLICT_FIX_LEASE_MARKER,
+            "pr: #376",
+            "phase: released",
+            # missing head_before and profile
+        ])
+        claim_body = _conflict_fix_body(phase="claimed")
+        comments = [{"body": claim_body}, {"body": malformed_release}]
+        lease = find_active_conflict_fix_lease(comments, pr_number=376, now=NOW)
+        self.assertIsNotNone(lease)
+
+    def test_pr818_historical_sequence(self):
+        comment_14696 = "\n".join([
+            "<!-- mcp-conflict-fix-lease:v1 -->",
+            "pr: #818",
+            "branch: feat/issue-638-webui-app-shell-phase1",
+            "worktree: /Users/jasonwalker/Development/Gitea-Tools/branches/issue-638-webui-app-shell-phase1",
+            "profile: prgs-author",
+            "session_id: unknown",
+            "phase: claimed",
+            "head_before: 08061b7b8aebdd099a37d1abf5dafcf38e4fd3fb",
+            "expires_at: 2026-07-23T07:12:13Z",
+            "reviewer_active: no",
+        ])
+        comment_14730 = "\n".join([
+            "<!-- mcp-conflict-fix-lease:v1 -->",
+            "pr: #818",
+            "branch: feat/issue-638-webui-app-shell-phase1",
+            "worktree: /Users/jasonwalker/Development/Gitea-Tools/branches/issue-638-webui-app-shell-phase1",
+            "profile: prgs-author",
+            "session_id: prgs-author-61241-e5129c60",
+            "phase: released",
+            "head_before: 08061b7b8aebdd099a37d1abf5dafcf38e4fd3fb",
+            "head_after: 64b6eb5d5402663098de5ded3b0617cc3b3df98f",
+            "expires_at: 2026-07-23T06:05:00Z",
+            "reviewer_active: no",
+        ])
+        comments = [{"body": comment_14696}, {"body": comment_14730}]
+        check_now = datetime(2026, 7, 23, 6, 30, tzinfo=timezone.utc)
+        lease = find_active_conflict_fix_lease(comments, pr_number=818, now=check_now)
+        self.assertIsNone(lease)
+        
+        reviewer_gate = assess_reviewer_mutation_blocked(
+            pr_number=818,
+            comments=comments,
+            reviewed_head_sha="64b6eb5d5402663098de5ded3b0617cc3b3df98f",
+            live_head_sha="64b6eb5d5402663098de5ded3b0617cc3b3df98f",
+            mutation="approve",
+            now=check_now,
+        )
+        self.assertTrue(reviewer_gate["mutation_allowed"])
+
+
 if __name__ == "__main__":
     unittest.main()

tests/test_restart_coordinator.py

@@ -0,0 +1,340 @@
+"""Tests for the MCP restart coordinator and impact analysis (#658).
+
+Multi-session fixtures exercise every verdict branch: safe, unsafe (live work),
+override, and the fail-closed deny on incomplete inventory. Also covers the
+critical-section deny path and the new ``ControlPlaneDB.list_sessions``.
+"""
+
+from __future__ import annotations
+
+import os
+import tempfile
+import unittest
+from datetime import datetime, timedelta, timezone
+
+import restart_coordinator as rc
+from control_plane_db import ControlPlaneDB
+
+
+NOW = datetime(2026, 7, 24, 6, 0, 0, tzinfo=timezone.utc)
+
+
+def _ts(dt: datetime) -> str:
+    return dt.isoformat()
+
+
+def _live_pid() -> int:
+    return os.getpid()
+
+
+def _dead_pid() -> int:
+    # A pid that is essentially never alive. os.kill(0) on it raises
+    # ProcessLookupError → is_process_alive False.
+    return 2_000_000_000
+
+
+def _session(session_id, *, pid, status="active", heartbeat=None, role="author"):
+    return {
+        "session_id": session_id,
+        "role": role,
+        "profile": "prgs-author",
+        "pid": pid,
+        "status": status,
+        "last_heartbeat_at": _ts(heartbeat or NOW),
+    }
+
+
+def _lease(
+    lease_id,
+    *,
+    session_id,
+    freshness,
+    kind="issue",
+    number=658,
+    phase="allocated",
+    worktree=None,
+    role="author",
+):
+    return {
+        "lease_id": lease_id,
+        "session_id": session_id,
+        "role": role,
+        "phase": phase,
+        "work_kind": kind,
+        "work_number": number,
+        "worktree_path": worktree,
+        "freshness": {"freshness": freshness},
+    }
+
+
+class EvaluateRestartImpactTest(unittest.TestCase):
+    def test_incomplete_inventory_denies_fail_closed(self) -> None:
+        report = rc.evaluate_restart_impact(
+            {"inventory_complete": False, "incomplete_reasons": ["db down"]},
+            now=NOW,
+        )
+        self.assertEqual(report.verdict, rc.VERDICT_UNSAFE)
+        self.assertFalse(report.allow_restart)
+        self.assertFalse(report.restart_performed)
+        self.assertIn("db down", report.incomplete_reasons)
+        self.assertTrue(
+            any("fail closed" in reasoning for reasoning in report.reasons)
+        )
+
+    def test_missing_completeness_flag_denies(self) -> None:
+        # No inventory_complete key at all → treated as incomplete.
+        report = rc.evaluate_restart_impact({}, now=NOW)
+        self.assertEqual(report.verdict, rc.VERDICT_UNSAFE)
+        self.assertFalse(report.allow_restart)
+
+    def test_no_other_work_is_safe(self) -> None:
+        report = rc.evaluate_restart_impact(
+            {
+                "inventory_complete": True,
+                "sessions": [_session("requester", pid=_live_pid())],
+                "leases": [],
+            },
+            now=NOW,
+            requesting_session_id="requester",
+        )
+        self.assertEqual(report.verdict, rc.VERDICT_SAFE)
+        self.assertTrue(report.allow_restart)
+        self.assertEqual(report.blast_radius, rc.BLAST_NONE)
+        self.assertEqual(report.affected_issues, [])
+
+    def test_dead_foreign_session_and_lease_are_not_disruptive(self) -> None:
+        report = rc.evaluate_restart_impact(
+            {
+                "inventory_complete": True,
+                "sessions": [
+                    _session("requester", pid=_live_pid()),
+                    _session("dead", pid=_dead_pid()),
+                ],
+                "leases": [
+                    _lease("l-dead", session_id="dead", freshness="stale_dead_process")
+                ],
+            },
+            now=NOW,
+            requesting_session_id="requester",
+        )
+        self.assertEqual(report.verdict, rc.VERDICT_SAFE)
+        self.assertTrue(report.allow_restart)
+        self.assertEqual(report.counts["leases_disruptive"], 0)
+        self.assertEqual(report.counts["sessions_live_other"], 0)
+
+    def test_live_foreign_lease_denies_without_override(self) -> None:
+        report = rc.evaluate_restart_impact(
+            {
+                "inventory_complete": True,
+                "sessions": [
+                    _session("requester", pid=_live_pid()),
+                    _session("worker", pid=_live_pid()),
+                ],
+                "leases": [
+                    _lease(
+                        "l1",
+                        session_id="worker",
+                        freshness="active",
+                        worktree="/tmp/wt-658",
+                        phase="implementing",
+                    )
+                ],
+            },
+            now=NOW,
+            requesting_session_id="requester",
+        )
+        self.assertEqual(report.verdict, rc.VERDICT_UNSAFE)
+        self.assertFalse(report.allow_restart)
+        # Critical section detected: active lease with a live owner.
+        self.assertEqual(len(report.critical_sections), 1)
+        self.assertEqual(report.affected_issues, [658])
+        self.assertEqual(report.counts["mutations"], 1)
+        self.assertTrue(report.override_would_allow)
+        self.assertEqual(report.blast_radius, rc.BLAST_HIGH)
+        # Placeholder ack state for the affected session.
+        self.assertEqual(report.ack_state.get("worker"), "pending")
+
+    def test_operator_override_allows_despite_live_work(self) -> None:
+        inv = {
+            "inventory_complete": True,
+            "sessions": [
+                _session("requester", pid=_live_pid()),
+                _session("worker", pid=_live_pid()),
+            ],
+            "leases": [_lease("l1", session_id="worker", freshness="active")],
+        }
+        report = rc.evaluate_restart_impact(
+            inv,
+            now=NOW,
+            requesting_session_id="requester",
+            operator_override=True,
+        )
+        self.assertEqual(report.verdict, rc.VERDICT_OVERRIDE)
+        self.assertTrue(report.allow_restart)
+        self.assertFalse(report.restart_performed)
+
+    def test_deny_when_critical_section_open(self) -> None:
+        # A single live author lease in a mutating phase is a critical section
+        # that must deny an un-overridden restart.
+        report = rc.evaluate_restart_impact(
+            {
+                "inventory_complete": True,
+                "sessions": [_session("worker", pid=_live_pid())],
+                "leases": [
+                    _lease(
+                        "l1",
+                        session_id="worker",
+                        freshness="active",
+                        phase="merging",
+                        kind="pr",
+                        number=900,
+                    )
+                ],
+            },
+            now=NOW,
+            requesting_session_id="requester",
+        )
+        self.assertEqual(report.verdict, rc.VERDICT_UNSAFE)
+        self.assertFalse(report.allow_restart)
+        self.assertEqual(report.affected_prs, [900])
+        self.assertEqual(len(report.critical_sections), 1)
+
+    def test_terminal_lock_makes_restart_unsafe(self) -> None:
+        report = rc.evaluate_restart_impact(
+            {
+                "inventory_complete": True,
+                "sessions": [_session("requester", pid=_live_pid())],
+                "leases": [],
+                "terminal_lock": {"terminal_pr": 812},
+            },
+            now=NOW,
+            requesting_session_id="requester",
+        )
+        self.assertEqual(report.verdict, rc.VERDICT_UNSAFE)
+        self.assertFalse(report.allow_restart)
+        self.assertIsNotNone(report.terminal_lock)
+        self.assertTrue(
+            any("terminal" in reasoning for reasoning in report.reasons)
+        )
+
+    def test_other_live_session_without_lease_is_disruptive(self) -> None:
+        report = rc.evaluate_restart_impact(
+            {
+                "inventory_complete": True,
+                "sessions": [
+                    _session("requester", pid=_live_pid()),
+                    _session("idle-but-live", pid=_live_pid()),
+                ],
+                "leases": [],
+            },
+            now=NOW,
+            requesting_session_id="requester",
+        )
+        self.assertEqual(report.verdict, rc.VERDICT_UNSAFE)
+        self.assertEqual(report.counts["sessions_live_other"], 1)
+
+    def test_stale_heartbeat_session_not_counted_live(self) -> None:
+        stale = NOW - timedelta(hours=2)
+        report = rc.evaluate_restart_impact(
+            {
+                "inventory_complete": True,
+                "sessions": [
+                    _session("requester", pid=_live_pid()),
+                    _session("stale", pid=_live_pid(), heartbeat=stale),
+                ],
+                "leases": [],
+            },
+            now=NOW,
+            requesting_session_id="requester",
+        )
+        self.assertEqual(report.verdict, rc.VERDICT_SAFE)
+        self.assertEqual(report.counts["sessions_live_other"], 0)
+
+    def test_prior_recovery_attempts_echoed(self) -> None:
+        report = rc.evaluate_restart_impact(
+            {
+                "inventory_complete": True,
+                "sessions": [_session("requester", pid=_live_pid())],
+                "leases": [],
+                "prior_recovery_attempts": [
+                    {"kind": "client_reconnect", "at": _ts(NOW)}
+                ],
+            },
+            now=NOW,
+            requesting_session_id="requester",
+        )
+        self.assertEqual(len(report.prior_recovery_attempts), 1)
+        self.assertEqual(report.counts["prior_recovery_attempts"], 1)
+
+    def test_bare_string_freshness_accepted(self) -> None:
+        lease = _lease("l1", session_id="worker", freshness="active")
+        lease["freshness"] = "active"  # bare string, not a dict
+        report = rc.evaluate_restart_impact(
+            {
+                "inventory_complete": True,
+                "sessions": [_session("worker", pid=_live_pid())],
+                "leases": [lease],
+            },
+            now=NOW,
+            requesting_session_id="requester",
+        )
+        self.assertEqual(report.counts["leases_disruptive"], 1)
+
+    def test_as_dict_is_serializable_dto(self) -> None:
+        import json
+
+        report = rc.evaluate_restart_impact(
+            {
+                "inventory_complete": True,
+                "sessions": [_session("requester", pid=_live_pid())],
+                "leases": [],
+            },
+            now=NOW,
+            requesting_session_id="requester",
+        )
+        payload = report.as_dict()
+        # Round-trips through JSON — safe for the console DTO.
+        encoded = json.dumps(payload)
+        decoded = json.loads(encoded)
+        self.assertEqual(decoded["verdict"], rc.VERDICT_SAFE)
+        self.assertIn("audit_record", decoded)
+        self.assertEqual(decoded["audit_record"]["event"], "restart_impact_evaluated")
+        self.assertFalse(decoded["restart_performed"])
+        self.assertIn("coordinator_version", decoded)
+
+
+class ListSessionsTest(unittest.TestCase):
+    def setUp(self) -> None:
+        self._tmp = tempfile.TemporaryDirectory()
+        self.db = ControlPlaneDB(os.path.join(self._tmp.name, "cp.sqlite3"))
+
+    def tearDown(self) -> None:
+        self._tmp.cleanup()
+
+    def test_list_sessions_filters_by_status(self) -> None:
+        self.db.upsert_session(session_id="a", role="author", pid=1, status="active")
+        self.db.upsert_session(session_id="b", role="author", pid=2, status="ended")
+        active = self.db.list_sessions(statuses=("active",))
+        ids = {row["session_id"] for row in active}
+        self.assertEqual(ids, {"a"})
+        every = self.db.list_sessions()
+        self.assertEqual({row["session_id"] for row in every}, {"a", "b"})
+
+    def test_list_sessions_feeds_coordinator(self) -> None:
+        self.db.upsert_session(
+            session_id="requester", role="author", pid=os.getpid(), status="active"
+        )
+        report = rc.evaluate_restart_impact(
+            {
+                "inventory_complete": True,
+                "sessions": self.db.list_sessions(statuses=("active",)),
+                "leases": [],
+            },
+            now=NOW,
+            requesting_session_id="requester",
+        )
+        self.assertEqual(report.counts["sessions_total"], 1)
+
+
+if __name__ == "__main__":  # pragma: no cover
+    unittest.main()

tests/test_webui_system_health_dashboard.py

@@ -0,0 +1,345 @@
+"""Tests for the system-health dashboard view (#639).
+
+Covers the acceptance criteria directly: the page renders the health DTO
+fields (AC1), degraded dependencies are visible (AC2), stale runtime is warned
+prominently and never rendered as mutation-safe (AC3), healthy and degraded
+fixtures both render (AC4), and the shell carries a nav entry (AC5).
+"""
+import sys
+import unittest
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+from starlette.testclient import TestClient
+
+from webui.app import create_app
+from webui.deployment_boundary import scan_text_for_client_secrets
+from webui.layout import render_page
+from webui.nav import iter_nav_items
+from webui.system_health import (
+    STATUS_DEGRADED,
+    STATUS_DOWN,
+    STATUS_OK,
+    STATUS_SKIPPED,
+    STATUS_UNPROVEN,
+    DependencyProbe,
+    StaleRuntime,
+    SystemHealthSnapshot,
+    VersionInfo,
+)
+from webui.system_health_views import render_system_health_page
+
+DASHBOARD_PATH = "/system-health"
+
+
+def _version(*, known: bool = True) -> VersionInfo:
+    return VersionInfo(
+        git_sha="1c455b6ec0f9cb761fe6248de68c17e061fb5ecd" if known else None,
+        git_describe="v0.4.1-12-g1c455b6" if known else None,
+        control_plane_schema_version=4 if known else None,
+        python_version="3.13.1",
+        known=known,
+    )
+
+
+def _parity(*, stale: bool = False, determinable: bool = True) -> StaleRuntime:
+    if stale:
+        return StaleRuntime(
+            daemon_head="aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+            checkout_head="bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
+            remote_head="cccccccccccccccccccccccccccccccccccccccc",
+            stale=True,
+            determinable=True,
+            mutation_safe=False,
+            reasons=("runtime, checkout, and remote commits disagree",),
+        )
+    if not determinable:
+        return StaleRuntime(
+            daemon_head=None,
+            checkout_head=None,
+            remote_head=None,
+            stale=False,
+            determinable=False,
+            mutation_safe=False,
+            reasons=("local checkout HEAD could not be read",),
+        )
+    return StaleRuntime(
+        daemon_head="1c455b6ec0f9cb761fe6248de68c17e061fb5ecd",
+        checkout_head="1c455b6ec0f9cb761fe6248de68c17e061fb5ecd",
+        remote_head="1c455b6ec0f9cb761fe6248de68c17e061fb5ecd",
+        stale=False,
+        determinable=True,
+        mutation_safe=True,
+        reasons=(),
+    )
+
+
+def _snapshot(
+    *,
+    status: str = STATUS_OK,
+    ready: bool = True,
+    readiness_complete: bool = True,
+    readiness_reasons: tuple[str, ...] = (),
+    dependencies: tuple[DependencyProbe, ...] | None = None,
+    parity: StaleRuntime | None = None,
+    namespaces: tuple[dict, ...] = (),
+    probe_errors: tuple[str, ...] = (),
+    version_known: bool = True,
+) -> SystemHealthSnapshot:
+    if dependencies is None:
+        dependencies = (
+            DependencyProbe(
+                name="control_plane_db",
+                kind="sqlite",
+                status=STATUS_OK,
+                detail="schema version 4",
+                required=True,
+                latency_ms=1.25,
+                metadata={"schema_version": 4},
+            ),
+        )
+    return SystemHealthSnapshot(
+        status=status,
+        ready=ready,
+        readiness_complete=readiness_complete,
+        readiness_reasons=readiness_reasons,
+        service="mcp-control-plane-webui",
+        mode="read-only",
+        version=_version(known=version_known),
+        started_at="2026-07-23T19:50:47+00:00",
+        uptime_seconds=3661.5,
+        timestamp="2026-07-23T20:51:48+00:00",
+        deep_probes_requested=False,
+        dependencies=dependencies,
+        mcp_namespaces=namespaces,
+        stale_runtime=parity if parity is not None else _parity(),
+        probe_errors=probe_errors,
+    )
+
+
+class TestHealthyRender(unittest.TestCase):
+    """AC1 / AC4 — every health DTO field reaches the page."""
+
+    def setUp(self):
+        self.html = render_system_health_page(_snapshot())
+
+    def test_readiness_fields_render(self):
+        self.assertIn("System health", self.html)
+        self.assertIn("Ready", self.html)
+        self.assertIn("mcp-control-plane-webui", self.html)
+        self.assertIn("read-only", self.html)
+        self.assertIn("2026-07-23T20:51:48+00:00", self.html)
+
+    def test_version_and_uptime_render(self):
+        self.assertIn("1c455b6ec0f9cb761fe6248de68c17e061fb5ecd", self.html)
+        self.assertIn("v0.4.1-12-g1c455b6", self.html)
+        self.assertIn("3.13.1", self.html)
+        self.assertIn("3661.500s", self.html)
+        self.assertIn("1.02h", self.html)
+
+    def test_dependency_row_renders_with_latency(self):
+        self.assertIn("control_plane_db", self.html)
+        self.assertIn("sqlite", self.html)
+        self.assertIn("schema version 4", self.html)
+        self.assertIn("1.2 ms", self.html)
+
+    def test_healthy_page_shows_no_stale_warning(self):
+        self.assertNotIn("Stale runtime:", self.html)
+        self.assertNotIn("Staleness", self.html)
+
+    def test_unknown_version_is_labelled_not_faked(self):
+        html = render_system_health_page(_snapshot(version_known=False))
+        self.assertIn("unknown", html)
+        self.assertIn("unresolved", html)
+
+
+class TestDegradedRender(unittest.TestCase):
+    """AC2 — a degraded or unrun dependency is visible, not swallowed."""
+
+    def setUp(self):
+        self.deps = (
+            DependencyProbe(
+                name="control_plane_db",
+                kind="sqlite",
+                status=STATUS_OK,
+                detail="schema version 4",
+                required=True,
+                latency_ms=0.9,
+            ),
+            DependencyProbe(
+                name="repository",
+                kind="git",
+                status=STATUS_DOWN,
+                detail="repository root is not a git checkout",
+                required=True,
+                latency_ms=4.0,
+            ),
+            DependencyProbe(
+                name="gitea",
+                kind="http",
+                status=STATUS_SKIPPED,
+                detail="deep probe not requested",
+                required=False,
+            ),
+        )
+        self.html = render_system_health_page(
+            _snapshot(
+                status=STATUS_DEGRADED,
+                ready=False,
+                readiness_complete=False,
+                readiness_reasons=("required dependency 'repository' is down",),
+                dependencies=self.deps,
+            )
+        )
+
+    def test_degraded_banner_names_the_dependency(self):
+        self.assertIn("Degraded dependencies:", self.html)
+        self.assertIn("repository", self.html)
+
+    def test_not_run_probe_is_reported_separately(self):
+        self.assertIn("Not probed:", self.html)
+        self.assertIn("gitea", self.html)
+        self.assertIn("not counted", self.html)
+
+    def test_not_ready_headline_and_reason(self):
+        self.assertIn("Not ready", self.html)
+        self.assertIn("required dependency 'repository' is down", self.html)
+
+    def test_degraded_status_badge_present(self):
+        self.assertIn("badge-health-degraded", self.html)
+        self.assertIn("badge-health-down", self.html)
+
+    def test_ready_but_incomplete_is_not_shown_as_plain_ready(self):
+        html = render_system_health_page(
+            _snapshot(ready=True, readiness_complete=False)
+        )
+        self.assertIn("Ready (incomplete evidence)", html)
+
+
+class TestStaleRuntimeWarning(unittest.TestCase):
+    """AC3 — staleness is prominent and never claims mutation safety."""
+
+    def test_stale_runtime_warns_and_denies_mutation_safety(self):
+        html = render_system_health_page(_snapshot(parity=_parity(stale=True)))
+        self.assertIn("Stale runtime:", html)
+        self.assertIn("do not treat this runtime as mutation-safe", html)
+        self.assertIn("<tr><th>Mutation safe</th><td>False</td></tr>", html)
+
+    def test_indeterminate_parity_is_not_reported_safe(self):
+        html = render_system_health_page(
+            _snapshot(parity=_parity(determinable=False))
+        )
+        self.assertIn("Staleness", html)
+        self.assertIn("<tr><th>Mutation safe</th><td>False</td></tr>", html)
+        self.assertIn("<tr><th>Determinable</th><td>False</td></tr>", html)
+
+    def test_healthy_parity_reports_mutation_safe_true(self):
+        html = render_system_health_page(_snapshot())
+        self.assertIn("<tr><th>Mutation safe</th><td>True</td></tr>", html)
+
+
+class TestNamespacesAndErrors(unittest.TestCase):
+    def test_unproven_namespace_rows_render(self):
+        html = render_system_health_page(
+            _snapshot(
+                namespaces=(
+                    {
+                        "namespace": "gitea-author",
+                        "required_tool": "gitea_lock_issue",
+                        "status": STATUS_UNPROVEN,
+                        "ide_namespace_proven": False,
+                        "reason": "the web console cannot invoke the IDE-managed MCP client",
+                    },
+                )
+            )
+        )
+        self.assertIn("gitea-author", html)
+        self.assertIn("gitea_lock_issue", html)
+        self.assertIn("badge-health-unproven", html)
+
+    def test_no_namespaces_degrades_gracefully(self):
+        html = render_system_health_page(_snapshot(namespaces=()))
+        self.assertIn("No MCP namespaces are declared.", html)
+
+    def test_probe_errors_render_when_present(self):
+        html = render_system_health_page(
+            _snapshot(probe_errors=("probe raised: disk offline",))
+        )
+        self.assertIn("Probe errors", html)
+        self.assertIn("disk offline", html)
+
+    def test_probe_error_card_absent_when_clean(self):
+        self.assertNotIn("Probe errors", render_system_health_page(_snapshot()))
+
+
+class TestReadOnlyAndRedaction(unittest.TestCase):
+    def test_no_restart_or_kill_controls(self):
+        html = render_system_health_page(_snapshot())
+        self.assertNotIn("<button", html)
+        self.assertNotIn("<form", html)
+        self.assertNotIn("pkill", html)
+        self.assertIn("read-only", html)
+
+    def test_recovery_points_at_sanctioned_path(self):
+        html = render_system_health_page(_snapshot())
+        self.assertIn("Reconnect the MCP client", html)
+        self.assertIn("Never kill the daemon process manually", html)
+
+    def test_secret_shaped_detail_is_redacted(self):
+        leaky = DependencyProbe(
+            name="gitea",
+            kind="http",
+            status=STATUS_DOWN,
+            detail="auth failed for token=ghp_ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789",
+            required=False,
+            latency_ms=12.0,
+        )
+        html = render_system_health_page(_snapshot(dependencies=(leaky,)))
+        self.assertNotIn("ghp_ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789", html)
+
+    def test_html_in_detail_is_escaped(self):
+        hostile = DependencyProbe(
+            name="repository",
+            kind="git",
+            status=STATUS_DOWN,
+            detail="<script>alert(1)</script>",
+            required=True,
+        )
+        html = render_system_health_page(_snapshot(dependencies=(hostile,)))
+        self.assertNotIn("<script>", html)
+        self.assertIn("&lt;script&gt;", html)
+
+
+class TestNavAndRoute(unittest.TestCase):
+    """AC5 — the shell links the dashboard, and the route serves it."""
+
+    def setUp(self):
+        self.client = TestClient(create_app())
+
+    def test_nav_contains_system_health(self):
+        self.assertIn(
+            (DASHBOARD_PATH, "System health"),
+            [(item.href, item.label) for item in iter_nav_items()],
+        )
+
+    def test_rendered_shell_links_dashboard(self):
+        page = render_page(title="Home", body_html="<p>x</p>")
+        self.assertIn(f'href="{DASHBOARD_PATH}"', page)
+
+    def test_route_renders_dashboard(self):
+        response = self.client.get(DASHBOARD_PATH)
+        self.assertEqual(response.status_code, 200)
+        self.assertIn("System health", response.text)
+        self.assertIn("Stale-runtime parity", response.text)
+
+    def test_route_is_read_only(self):
+        self.assertEqual(self.client.post(DASHBOARD_PATH).status_code, 405)
+
+    def test_live_page_leaks_no_client_secret(self):
+        findings = scan_text_for_client_secrets(self.client.get(DASHBOARD_PATH).text)
+        self.assertEqual(findings, [])
+
+
+if __name__ == "__main__":  # pragma: no cover
+    unittest.main()

tests/test_worktree_cleanup_audit.py

@@ -134,13 +134,35 @@ class TestClassification(unittest.TestCase):
         self.assertEqual(cls, wca.CLASS_ACTIVE_OPEN_PR)
         self.assertFalse(wca.is_removable(cls))
 
-    def test_stale_clean_issue_worktree_removable(self):
+    def test_stale_clean_issue_worktree_needs_merged_pr_proof(self):
-        # Scenario 5: clean issue worktree, TTL expired, no lock -> removable.
+        # Scenario 5 (#858): age is not proof that the branch landed, so a
+        # TTL-expired issue worktree stays active work. Only authoritative
+        # merged-PR evidence makes it removable, which is what keeps a
+        # worktree holding unmerged commits from being reclaimed by age.
         cls = wca.classify_worktree(
             workflow_type=wca.WORKFLOW_ISSUE_WORK,
             is_dirty=False,
             ttl_expired=True,
         )
+        self.assertEqual(cls, wca.CLASS_ACTIVE_ISSUE_WORK)
+        self.assertFalse(wca.is_removable(cls))
+
+        cls = wca.classify_worktree(
+            workflow_type=wca.WORKFLOW_ISSUE_WORK,
+            is_dirty=False,
+            ttl_expired=True,
+            merged_pr_cleanup={"proven": True},
+        )
+        self.assertEqual(cls, wca.CLASS_CLEAN_STALE_REMOVABLE)
+        self.assertTrue(wca.is_removable(cls))
+
+    def test_stale_clean_conflict_fix_worktree_removable(self):
+        # conflict_fix keeps the original TTL rule; #858 changed issue work only.
+        cls = wca.classify_worktree(
+            workflow_type=wca.WORKFLOW_CONFLICT_FIX,
+            is_dirty=False,
+            ttl_expired=True,
+        )
         self.assertEqual(cls, wca.CLASS_CLEAN_STALE_REMOVABLE)
         self.assertTrue(wca.is_removable(cls))
 

webui/app.py

@@ -53,6 +53,7 @@ from webui.system_health import (
     process_uptime,
     snapshot_to_dict as system_health_to_dict,
 )
+from webui.system_health_views import render_system_health_page
 
 _READ_ONLY_METHODS = frozenset({"GET", "HEAD", "OPTIONS"})
 _AUDIT_MUTATION_PATHS = frozenset({"/audit", "/api/audit"})
@@ -161,6 +162,24 @@ async def api_system_health(request: Request) -> JSONResponse:
     return JSONResponse(payload, status_code=200 if snapshot.ready else 503)
 
 
+async def system_health(request: Request) -> HTMLResponse:
+    """Read-only system-health dashboard (#639).
+
+    Shares the #634 snapshot loader with the JSON API so the page can never
+    disagree with it. `?deep=1` opts into the network probe exactly as the API
+    does; the default page load stays cheap. The response is always 200: this
+    is an operator view that must render the degraded state, not withhold it.
+    """
+    deep = _truthy_flag(request.query_params.get("deep"))
+    snapshot = load_system_health(deep=deep)
+    return HTMLResponse(
+        render_page(
+            title="System health",
+            body_html=render_system_health_page(snapshot),
+        )
+    )
+
+
 async def queue(_request: Request) -> HTMLResponse:
     snapshot = load_queue_snapshot()
     return HTMLResponse(render_page(title="Queue", body_html=render_queue_page(snapshot)))
@@ -571,6 +590,7 @@ def create_app(*, bind_host: str | None = None) -> Starlette:
             Route("/", home, methods=["GET"]),
             Route("/health", health, methods=["GET"]),
             Route(SYSTEM_HEALTH_API_PATH, api_system_health, methods=["GET"]),
+            Route("/system-health", system_health, methods=["GET"]),
             Route("/queue", queue, methods=["GET"]),
             Route("/api/queue", api_queue, methods=["GET"]),
             Route("/projects", projects, methods=["GET"]),

webui/layout.py

@@ -236,6 +236,25 @@ def render_page(*, title: str, body_html: str, extra_head: str = "") -> str:
     .badge-in-review {{ color: #9ec8f0; border-color: #3d5f7a; }}
     .badge-duplicate {{ color: #e0c27a; border-color: #6b5730; }}
     .badge-stale {{ color: #c9b8e8; border-color: #5a4a78; }}
+    .badge-health-ok {{ color: #8fd19e; border-color: #3d6b4a; }}
+    .badge-health-degraded {{ color: #e0c27a; border-color: #6b5730; }}
+    .badge-health-down {{ color: #f0a8a8; border-color: #7a3b3b; }}
+    .badge-health-skipped {{ color: var(--muted); }}
+    .badge-health-unproven {{ color: #c9b8e8; border-color: #5a4a78; }}
+    .health-card {{
+      margin: 1.25rem 0;
+      padding: 0.85rem 1rem 1rem;
+      border: 1px solid var(--border);
+      border-radius: 8px;
+      background: var(--surface);
+    }}
+    .health-card h3 {{ margin: 0 0 0.5rem; font-size: 1.05rem; }}
+    .health-card h4 {{ margin: 1rem 0 0.35rem; font-size: 0.92rem; color: var(--muted); }}
+    .health-headline {{ color: var(--text); font-size: 1rem; margin: 0 0 0.5rem; }}
+    .health-degraded {{ border-left-color: #e0c27a; }}
+    .health-stale {{ border-left-color: #f0a8a8; }}
+    ul.reasons {{ margin: 0.35rem 0; padding-left: 1.15rem; color: var(--muted); font-size: 0.9rem; }}
+    ul.reasons li {{ margin-bottom: 0.3rem; }}
   </style>
   {extra_head}
 </head>

webui/nav.py

@@ -38,6 +38,7 @@ class NavGroup:
 NAV_GROUPS: tuple[NavGroup, ...] = (
     NavGroup("Health", (
         NavItem("/health", "Liveness"),
+        NavItem("/system-health", "System health"),
     )),
     NavGroup("Traffic", (
         NavItem("/queue", "Queue"),

webui/system_health_views.py

@@ -0,0 +1,307 @@
+"""HTML views for the system-health dashboard (#639).
+
+Renders the read-only :class:`~webui.system_health.SystemHealthSnapshot`
+produced by the Phase 1 system-health API (#634). The page offers no restart,
+reload, or process-kill control: those are Phase 2 work, and manual process
+kills are the contamination path #630 exists to prevent.
+
+Every free-text field passes through :func:`webui.system_health.redact` before
+it reaches HTML, so a probe detail that captured a token or a credentialed URL
+cannot leak through the dashboard even though the API redacts it already.
+"""
+
+from __future__ import annotations
+
+import html
+
+from webui.system_health import (
+    STATUS_DEGRADED,
+    STATUS_DOWN,
+    STATUS_OK,
+    STATUS_SKIPPED,
+    STATUS_UNPROVEN,
+    DependencyProbe,
+    SystemHealthSnapshot,
+    redact,
+)
+
+_STATUS_BADGE_CLASS = {
+    STATUS_OK: "badge-health-ok",
+    STATUS_DEGRADED: "badge-health-degraded",
+    STATUS_DOWN: "badge-health-down",
+    STATUS_SKIPPED: "badge-health-skipped",
+    STATUS_UNPROVEN: "badge-health-unproven",
+}
+
+
+def _safe(value: object) -> str:
+    """Escape free text for HTML after redacting anything secret-shaped.
+
+    Use this for every value that can carry arbitrary text — probe details,
+    reasons, probe errors — because those are where a credential could ride
+    along.
+    """
+    return html.escape(redact(str(value)))
+
+
+def _esc(value: object) -> str:
+    """Escape a structured field for HTML without redacting it.
+
+    Commit SHAs, probe names, statuses, and timestamps are enumerated or
+    machine-generated, never credential-bearing. They must not go through
+    :func:`redact`: its opaque-token rule matches any 32-plus-character run,
+    so a 40-character git SHA would render as ``[redacted]`` and the parity
+    view — the one thing an operator reads this page for — would be blank.
+    """
+    return html.escape(str(value))
+
+
+def _status_badge(status: str) -> str:
+    css = _STATUS_BADGE_CLASS.get(status, "badge-health-unproven")
+    return f'<span class="badge {css}">{_esc(status)}</span>'
+
+
+def _reason_list(reasons: tuple[str, ...], *, empty: str) -> str:
+    if not reasons:
+        return f"<p class='muted'>{html.escape(empty)}</p>"
+    items = "".join(f"<li>{_safe(reason)}</li>" for reason in reasons)
+    return f"<ul class='reasons'>{items}</ul>"
+
+
+def _readiness_card(snapshot: SystemHealthSnapshot) -> str:
+    """Overall readiness.
+
+    ``ready`` and ``readiness_complete`` are shown separately on purpose: a
+    snapshot whose required probes never ran is not the same as one that ran
+    them and passed, and collapsing the two would render an unproven green.
+    """
+    if snapshot.ready and snapshot.readiness_complete:
+        headline = "Ready"
+    elif snapshot.ready:
+        headline = "Ready (incomplete evidence)"
+    else:
+        headline = "Not ready"
+
+    return (
+        "<section class='health-card'>"
+        f"<h3>Readiness {_status_badge(snapshot.status)}</h3>"
+        f"<p class='health-headline'>{html.escape(headline)}</p>"
+        "<table class='detail'>"
+        f"<tr><th>Service</th><td><code>{_esc(snapshot.service)}</code></td></tr>"
+        f"<tr><th>Mode</th><td>{_esc(snapshot.mode)}</td></tr>"
+        f"<tr><th>Ready</th><td>{_esc(snapshot.ready)}</td></tr>"
+        "<tr><th>Readiness evidence complete</th>"
+        f"<td>{_esc(snapshot.readiness_complete)}</td></tr>"
+        "<tr><th>Deep probes requested</th>"
+        f"<td>{_esc(snapshot.deep_probes_requested)}</td></tr>"
+        f"<tr><th>Observed at</th><td><code>{_esc(snapshot.timestamp)}</code></td></tr>"
+        "</table>"
+        "<h4>Readiness reasons</h4>"
+        f"{_reason_list(snapshot.readiness_reasons, empty='No readiness objections recorded.')}"
+        "</section>"
+    )
+
+
+def _version_card(snapshot: SystemHealthSnapshot) -> str:
+    version = snapshot.version
+    uptime_hours = snapshot.uptime_seconds / 3600.0
+    known = (
+        "resolved"
+        if version.known
+        else "unresolved — version fields could not be read from the checkout"
+    )
+    schema = version.control_plane_schema_version
+    return (
+        "<section class='health-card'>"
+        "<h3>Version and uptime</h3>"
+        "<table class='detail'>"
+        f"<tr><th>Git SHA</th><td><code>{_esc(version.git_sha or 'unknown')}</code></td></tr>"
+        "<tr><th>Git describe</th>"
+        f"<td><code>{_esc(version.git_describe or 'unknown')}</code></td></tr>"
+        "<tr><th>Control-plane schema</th>"
+        f"<td>{_esc(schema if schema is not None else 'unknown')}</td></tr>"
+        f"<tr><th>Python</th><td><code>{_esc(version.python_version)}</code></td></tr>"
+        f"<tr><th>Version status</th><td>{html.escape(known)}</td></tr>"
+        f"<tr><th>Started at</th><td><code>{_esc(snapshot.started_at)}</code></td></tr>"
+        "<tr><th>Uptime</th>"
+        f"<td>{snapshot.uptime_seconds:.3f}s ({uptime_hours:.2f}h)</td></tr>"
+        "</table>"
+        "</section>"
+    )
+
+
+def _dependency_rows(probes: tuple[DependencyProbe, ...]) -> str:
+    if not probes:
+        return "<p class='muted'>No dependency probes were reported.</p>"
+    rows = []
+    for probe in probes:
+        latency = (
+            f"{probe.latency_ms:.1f} ms" if probe.latency_ms is not None else "n/a"
+        )
+        rows.append(
+            "<tr>"
+            f"<td><code>{_esc(probe.name)}</code></td>"
+            f"<td>{_esc(probe.kind)}</td>"
+            f"<td>{_status_badge(probe.status)}</td>"
+            f"<td>{_esc('required' if probe.required else 'optional')}</td>"
+            f"<td>{html.escape(latency)}</td>"
+            f"<td>{_safe(probe.detail)}</td>"
+            "</tr>"
+        )
+    return (
+        "<table class='registry'><thead><tr>"
+        "<th>Dependency</th><th>Kind</th><th>Status</th><th>Requirement</th>"
+        "<th>Latency</th><th>Detail</th>"
+        "</tr></thead><tbody>"
+        f"{''.join(rows)}</tbody></table>"
+    )
+
+
+def _dependency_card(snapshot: SystemHealthSnapshot) -> str:
+    degraded = [probe for probe in snapshot.dependencies if probe.ran and not probe.healthy]
+    not_run = [probe for probe in snapshot.dependencies if not probe.ran]
+
+    banner = ""
+    if degraded:
+        names = ", ".join(sorted(probe.name for probe in degraded))
+        banner += (
+            "<div class='stub health-degraded'><p><strong>Degraded dependencies:</strong> "
+            f"{_esc(names)}</p></div>"
+        )
+    if not_run:
+        names = ", ".join(sorted(probe.name for probe in not_run))
+        banner += (
+            "<div class='stub'><p><strong>Not probed:</strong> "
+            f"{_esc(names)} — these contribute no evidence and are not counted "
+            "as healthy.</p></div>"
+        )
+
+    return (
+        "<section class='health-card'>"
+        "<h3>Dependencies</h3>"
+        f"{banner}"
+        f"{_dependency_rows(snapshot.dependencies)}"
+        "<p class='muted'>Details are redacted at the API boundary and again "
+        "before rendering; credentials are never displayed.</p>"
+        "</section>"
+    )
+
+
+def _namespace_card(snapshot: SystemHealthSnapshot) -> str:
+    if not snapshot.mcp_namespaces:
+        body = "<p class='muted'>No MCP namespaces are declared.</p>"
+    else:
+        rows = []
+        for entry in snapshot.mcp_namespaces:
+            rows.append(
+                "<tr>"
+                f"<td><code>{_esc(entry.get('namespace'))}</code></td>"
+                f"<td><code>{_esc(entry.get('required_tool'))}</code></td>"
+                f"<td>{_status_badge(str(entry.get('status') or STATUS_UNPROVEN))}</td>"
+                f"<td>{_esc(entry.get('ide_namespace_proven'))}</td>"
+                f"<td>{_safe(entry.get('reason'))}</td>"
+                "</tr>"
+            )
+        body = (
+            "<table class='registry'><thead><tr>"
+            "<th>Namespace</th><th>Required tool</th><th>Status</th>"
+            "<th>IDE-proven</th><th>Reason</th>"
+            "</tr></thead><tbody>"
+            f"{''.join(rows)}</tbody></table>"
+        )
+    return (
+        "<section class='health-card'>"
+        "<h3>MCP namespaces</h3>"
+        f"{body}"
+        "<p class='muted'>The web process runs outside the IDE-managed MCP "
+        "client, so namespace health is reported as unproven rather than "
+        "guessed (#543).</p>"
+        "</section>"
+    )
+
+
+def _stale_runtime_card(snapshot: SystemHealthSnapshot) -> str:
+    stale = snapshot.stale_runtime
+    if stale.stale:
+        warning = (
+            "<div class='stub health-stale'><p><strong>Stale runtime:</strong> "
+            "the running code, the checkout, and the remote-tracking commit "
+            "disagree. Capability gates may be evaluating obsolete code — "
+            "do not treat this runtime as mutation-safe.</p></div>"
+        )
+    elif not stale.determinable:
+        warning = (
+            "<div class='stub health-stale'><p><strong>Staleness "
+            "indeterminate:</strong> parity could not be proven, so this "
+            "runtime is not reported as mutation-safe.</p></div>"
+        )
+    else:
+        warning = ""
+
+    return (
+        "<section class='health-card'>"
+        "<h3>Stale-runtime parity</h3>"
+        f"{warning}"
+        "<table class='detail'>"
+        "<tr><th>Daemon head</th>"
+        f"<td><code>{_esc(stale.daemon_head or 'unknown')}</code></td></tr>"
+        "<tr><th>Checkout head</th>"
+        f"<td><code>{_esc(stale.checkout_head or 'unknown')}</code></td></tr>"
+        "<tr><th>Remote head</th>"
+        f"<td><code>{_esc(stale.remote_head or 'unknown')}</code></td></tr>"
+        f"<tr><th>Stale</th><td>{_esc(stale.stale)}</td></tr>"
+        f"<tr><th>Determinable</th><td>{_esc(stale.determinable)}</td></tr>"
+        f"<tr><th>Mutation safe</th><td>{_esc(stale.mutation_safe)}</td></tr>"
+        "</table>"
+        f"{_reason_list(stale.reasons, empty='Runtime, checkout, and remote agree.')}"
+        "</section>"
+    )
+
+
+def _probe_error_card(snapshot: SystemHealthSnapshot) -> str:
+    if not snapshot.probe_errors:
+        return ""
+    return (
+        "<section class='health-card'>"
+        "<h3>Probe errors</h3>"
+        f"{_reason_list(snapshot.probe_errors, empty='')}"
+        "</section>"
+    )
+
+
+def _recovery_card() -> str:
+    """Sanctioned recovery pointers only — never a manual process kill (#630)."""
+    return (
+        "<section class='health-card'>"
+        "<h3>Recovery</h3>"
+        "<p class='muted'>This dashboard is read-only. Restart and reload "
+        "controls arrive in Phase 2 (#642); until then recovery runs through "
+        "the sanctioned client reconnect / operator restart path.</p>"
+        "<ul class='reasons'>"
+        "<li><a href='/runtime'>Runtime and session view</a> — active profile, "
+        "workflow hashes, and shell health.</li>"
+        "<li>Reconnect the MCP client from the IDE, then re-run the blocked "
+        "cycle. Never kill the daemon process manually: unmanaged kills are "
+        "recorded as runtime contamination (#630).</li>"
+        "<li>See <code>docs/webui-local-dev.md</code> for the documented "
+        "recovery sequence.</li>"
+        "</ul>"
+        "</section>"
+    )
+
+
+def render_system_health_page(snapshot: SystemHealthSnapshot) -> str:
+    """Render the full system-health dashboard body."""
+    return (
+        "<h2>System health</h2>"
+        "<p class='meta'>Read-only view of the Phase 1 system-health API "
+        "(<code>/api/v1/system/health</code>). Reload this page to refresh; "
+        "nothing here polls or mutates on your behalf.</p>"
+        f"{_readiness_card(snapshot)}"
+        f"{_stale_runtime_card(snapshot)}"
+        f"{_version_card(snapshot)}"
+        f"{_dependency_card(snapshot)}"
+        f"{_namespace_card(snapshot)}"
+        f"{_probe_error_card(snapshot)}"
+        f"{_recovery_card()}"
+    )

worktree_cleanup_audit.py

@@ -34,7 +34,11 @@ import subprocess
 from datetime import datetime, timezone
 from typing import Any
 
-from merged_cleanup_reconcile import branch_worktree_folder, read_local_worktree_state
+from merged_cleanup_reconcile import (
+    branch_worktree_folder,
+    is_head_ancestor_of_ref,
+    read_local_worktree_state,
+)
 from reviewer_worktree import parse_dirty_tracked_files, REVIEW_WORKTREE_RE
 
 PROTECTED_BRANCHES = frozenset({"master", "main", "dev"})
@@ -67,6 +71,14 @@ REMOVABLE_CLASSES = frozenset(
     {CLASS_CLEAN_STALE_REMOVABLE, CLASS_DETACHED_REVIEW_LEFTOVER}
 )
 
+# Merged-PR linkage outcomes for issue worktrees (#858). Only ``LINKAGE_MERGED``
+# is ownership proof; every other outcome leaves the worktree protected.
+LINKAGE_MERGED = "merged_pr"
+LINKAGE_OPEN = "open_pr"
+LINKAGE_NONE = "no_owning_pr"
+LINKAGE_AMBIGUOUS = "ambiguous"
+LINKAGE_UNKNOWN = "unknown"
+
 _ISSUE_REF_RE = re.compile(r"issue-(\d+)", re.IGNORECASE)
 _ISSUE_BRANCH_PREFIXES = ("feat/", "fix/", "docs/", "chore/")
 
@@ -169,6 +181,186 @@ def is_ttl_expired(
     return (now_dt - last).total_seconds() > ttl_hours * 3600.0
 
 
+def build_pr_index(prs: list[dict[str, Any]] | None) -> dict[str, list[dict[str, Any]]]:
+    """Index PR records by head branch for deterministic worktree linkage (#858).
+
+    Accepts Gitea PR payloads (``head`` as a dict) and pre-flattened records
+    (``head_branch``/``head_sha``). Records without a usable head branch or
+    number are dropped rather than guessed at, so a branch is only ever linked
+    to a PR the caller actually proved.
+    """
+    index: dict[str, list[dict[str, Any]]] = {}
+    for pr in prs or []:
+        head = pr.get("head")
+        if isinstance(head, dict):
+            head_branch = head.get("ref")
+            head_sha = head.get("sha")
+        else:
+            head_branch = pr.get("head_branch") or (head if isinstance(head, str) else None)
+            head_sha = pr.get("head_sha")
+        number = pr.get("number")
+        if not head_branch or number is None:
+            continue
+        try:
+            pr_number = int(number)
+        except (TypeError, ValueError):
+            continue
+        index.setdefault(str(head_branch).strip(), []).append(
+            {
+                "pr_number": pr_number,
+                "head_branch": str(head_branch).strip(),
+                "head_sha": head_sha,
+                "merged": bool(pr.get("merged") or pr.get("merged_at")),
+                "state": pr.get("state"),
+            }
+        )
+    return index
+
+
+def resolve_owning_pr(
+    *,
+    branch: str | None,
+    pr_index: dict[str, list[dict[str, Any]]] | None,
+) -> dict[str, Any]:
+    """Resolve the single PR that owns ``branch``, failing closed when unclear.
+
+    Ownership is only ``LINKAGE_MERGED`` when exactly one PR claims the branch
+    and that PR is merged. Several distinct PRs on one branch is a competing
+    claim (``LINKAGE_AMBIGUOUS``), and a still-open owner is reported as
+    ``LINKAGE_OPEN`` — both keep the worktree protected while still exposing
+    the PR number the audit resolved.
+    """
+    if pr_index is None:
+        return {
+            "status": LINKAGE_UNKNOWN,
+            "pr_number": None,
+            "candidate_pr_numbers": [],
+            "reasons": ["live PR state was not supplied; ownership unproven"],
+        }
+    branch_name = (branch or "").strip()
+    if not branch_name:
+        return {
+            "status": LINKAGE_UNKNOWN,
+            "pr_number": None,
+            "candidate_pr_numbers": [],
+            "reasons": ["worktree has no attached branch; ownership unproven"],
+        }
+
+    candidates = list(pr_index.get(branch_name) or [])
+    numbers = sorted({c["pr_number"] for c in candidates})
+    if not candidates:
+        return {
+            "status": LINKAGE_NONE,
+            "pr_number": None,
+            "candidate_pr_numbers": [],
+            "reasons": [f"no PR claims branch '{branch_name}'"],
+        }
+    if len(numbers) > 1:
+        return {
+            "status": LINKAGE_AMBIGUOUS,
+            "pr_number": None,
+            "candidate_pr_numbers": numbers,
+            "reasons": [
+                f"branch '{branch_name}' is claimed by competing PRs {numbers}; "
+                "ownership is ambiguous"
+            ],
+        }
+
+    owner = candidates[0]
+    pr_number = owner["pr_number"]
+    if owner.get("head_branch") != branch_name:
+        return {
+            "status": LINKAGE_UNKNOWN,
+            "pr_number": pr_number,
+            "candidate_pr_numbers": numbers,
+            "reasons": [
+                f"PR #{pr_number} head branch '{owner.get('head_branch')}' does not "
+                f"match worktree branch '{branch_name}'"
+            ],
+        }
+    if not owner.get("merged"):
+        return {
+            "status": LINKAGE_OPEN,
+            "pr_number": pr_number,
+            "candidate_pr_numbers": numbers,
+            "pr_head_sha": owner.get("head_sha"),
+            "reasons": [f"owning PR #{pr_number} is not merged"],
+        }
+    return {
+        "status": LINKAGE_MERGED,
+        "pr_number": pr_number,
+        "candidate_pr_numbers": numbers,
+        "pr_head_sha": owner.get("head_sha"),
+        "reasons": [],
+    }
+
+
+def assess_merged_pr_worktree_cleanup(
+    *,
+    linkage: dict[str, Any] | None,
+    head_sha: str | None,
+    head_in_master: bool | None,
+    is_dirty: bool,
+    has_open_pr: bool,
+    has_active_lease: bool,
+    has_active_issue_lock: bool,
+    is_protected: bool,
+    has_live_session: bool = False,
+) -> dict[str, Any]:
+    """Decide whether a merged issue worktree satisfies the full cleanup policy.
+
+    Every condition must be independently proven: conclusive merged-PR
+    ownership, agreement between the worktree branch and the PR head branch,
+    containment of the worktree head in authoritative master (which is what
+    proves no unmerged commits remain), absence of any open/competing PR,
+    lease, issue lock, or live session, a clean tree, and a worktree that is
+    not the protected control checkout. Anything unknown blocks.
+    """
+    link = linkage or {
+        "status": LINKAGE_UNKNOWN,
+        "pr_number": None,
+        "reasons": ["no linkage assessment supplied"],
+    }
+    status = link.get("status")
+    reasons: list[str] = []
+
+    if status != LINKAGE_MERGED:
+        reasons.extend(
+            link.get("reasons") or ["owning PR could not be conclusively identified"]
+        )
+    if is_protected:
+        reasons.append("worktree is protected or the stable control checkout")
+    if is_dirty:
+        reasons.append("worktree has uncommitted changes")
+    if has_open_pr:
+        reasons.append("worktree branch has an open PR")
+    if has_active_lease:
+        reasons.append("worktree has an active lease")
+    if has_active_issue_lock:
+        reasons.append("an active issue lock references this branch")
+    if has_live_session:
+        reasons.append("a live process or session is using this worktree")
+    if not head_sha:
+        reasons.append("worktree head sha is unknown")
+    if head_in_master is None:
+        reasons.append("containment of the worktree head in master is unknown")
+    elif not head_in_master:
+        reasons.append(
+            "worktree head is not contained in authoritative master "
+            "(unmerged commits remain)"
+        )
+
+    proven = not reasons
+    return {
+        "linkage_status": status,
+        "pr_number": link.get("pr_number"),
+        "pr_head_sha": link.get("pr_head_sha"),
+        "head_in_master": head_in_master,
+        "proven": proven,
+        "block_reasons": reasons,
+    }
+
+
 def classify_worktree(
     *,
     workflow_type: str,
@@ -181,6 +373,8 @@ def classify_worktree(
     ttl_expired: bool = False,
     is_protected: bool = False,
     metadata_known: bool = True,
+    merged_pr_cleanup: dict[str, Any] | None = None,
+    has_live_session: bool = False,
 ) -> str:
     """Classify a worktree, safety-first: any preservation signal wins.
 
@@ -199,6 +393,8 @@ def classify_worktree(
         return CLASS_ACTIVE_ISSUE_WORK  # never auto-deleted (criterion 8)
     if has_active_issue_lock:
         return CLASS_ACTIVE_ISSUE_WORK
+    if has_live_session:
+        return CLASS_ACTIVE_ISSUE_WORK  # a live session still owns this tree
     if not metadata_known or workflow_type == WORKFLOW_UNKNOWN:
         return CLASS_UNSAFE_UNKNOWN  # never auto-deleted without proof
 
@@ -207,7 +403,15 @@ def classify_worktree(
         if is_detached or branch_gone:
             return CLASS_DETACHED_REVIEW_LEFTOVER
         return CLASS_CLEAN_STALE_REMOVABLE
-    # issue_work / conflict_fix: only removable once the TTL has expired.
+    if workflow_type == WORKFLOW_ISSUE_WORK:
+        # #858: an issue worktree becomes removable only on authoritative
+        # merged-PR evidence satisfying the whole cleanup policy. Age alone
+        # never proves the branch landed, so TTL cannot qualify one by itself
+        # — otherwise a worktree holding unmerged commits would be reclaimed.
+        if (merged_pr_cleanup or {}).get("proven"):
+            return CLASS_CLEAN_STALE_REMOVABLE
+        return CLASS_ACTIVE_ISSUE_WORK
+    # conflict_fix: only removable once the TTL has expired.
     if ttl_expired:
         return CLASS_CLEAN_STALE_REMOVABLE
     return CLASS_ACTIVE_ISSUE_WORK
@@ -400,6 +604,20 @@ def remove_worktree(project_root: str, path: str) -> dict[str, Any]:
     }
 
 
+def head_contained_in_ref(
+    project_root: str, head_sha: str | None, ref: str | None
+) -> bool | None:
+    """Return True when ``head_sha`` is already contained in ``ref``.
+
+    Shares :mod:`merged_cleanup_reconcile`'s ancestry check so the audit and
+    the PR-scoped reconciler agree on what "already landed" means (#858).
+    Returns None when containment cannot be determined, which fails closed.
+    """
+    if not head_sha or not ref:
+        return None
+    return is_head_ancestor_of_ref(project_root, head_sha, ref)
+
+
 def _is_under_branches(project_root: str, path: str) -> bool:
     branches_root = os.path.join(os.path.abspath(project_root), "branches")
     return os.path.abspath(path or "").startswith(branches_root + os.sep)
@@ -413,16 +631,30 @@ def audit_branches_directory(
     active_issue_branches: set[str] | None = None,
     now: datetime | str | None = None,
     ttl_hours: float = DEFAULT_TTL_HOURS,
+    pr_index: dict[str, list[dict[str, Any]]] | None = None,
+    leased_issue_numbers: set[int] | None = None,
+    live_session_paths: set[str] | None = None,
+    master_ref: str | None = None,
 ) -> dict[str, Any]:
     """Classify every session-owned worktree under ``branches/``.
 
     Read-only: shells out to git for discovery and dirty state, then applies
     the pure classifier. Returns per-worktree classifications, counts, the
     list of removable candidates, and the ``git worktree list`` proof.
+
+    ``pr_index`` (see :func:`build_pr_index`) supplies the authoritative PR
+    ownership used to link issue worktrees to their merged PR (#858).
+    ``master_ref`` is the ref a worktree head must be contained in before it
+    can be considered landed. Both are optional and their absence only ever
+    fails closed: without them no issue worktree becomes removable.
     """
     open_pr_branches = open_pr_branches or set()
     leased_branches = leased_branches or set()
     active_issue_branches = active_issue_branches or set()
+    leased_issue_numbers = leased_issue_numbers or set()
+    live_session_paths = {
+        os.path.abspath(p) for p in (live_session_paths or set()) if p
+    }
 
     worktrees: list[dict[str, Any]] = []
     for entry in list_worktrees(project_root):
@@ -433,12 +665,42 @@ def audit_branches_directory(
         )
         dirty_state = read_worktree_dirty(path)
         is_dirty = bool(dirty_state.get("dirty"))
+        head_sha = entry.get("head")
+        linkage = resolve_owning_pr(branch=branch, pr_index=pr_index)
         metadata = build_worktree_metadata(
-            path=path, branch=branch, head_sha=entry.get("head")
+            path=path,
+            branch=branch,
+            head_sha=head_sha,
+            pr_number=linkage.get("pr_number"),
         )
         has_open_pr = bool(branch) and branch in open_pr_branches
-        has_active_lease = bool(branch) and branch in leased_branches
+        # A lease on issue N protects that issue's own work worktree. It must
+        # not incidentally protect a baseline/review scratch tree that merely
+        # carries the same issue marker in its name, which would change the
+        # classification of worktrees this policy does not own.
+        has_active_lease = (bool(branch) and branch in leased_branches) or (
+            metadata["workflow_type"] == WORKFLOW_ISSUE_WORK
+            and metadata.get("issue_number") is not None
+            and metadata["issue_number"] in leased_issue_numbers
+        )
         has_active_lock = bool(branch) and branch in active_issue_branches
+        has_live_session = bool(path) and os.path.abspath(path) in live_session_paths
+        head_in_master = (
+            head_contained_in_ref(project_root, head_sha, master_ref)
+            if master_ref
+            else None
+        )
+        merged_pr_cleanup = assess_merged_pr_worktree_cleanup(
+            linkage=linkage,
+            head_sha=head_sha,
+            head_in_master=head_in_master,
+            is_dirty=is_dirty,
+            has_open_pr=has_open_pr,
+            has_active_lease=has_active_lease,
+            has_active_issue_lock=has_active_lock,
+            is_protected=is_protected,
+            has_live_session=has_live_session,
+        )
         ttl_expired = is_ttl_expired(
             last_used_at=metadata.get("last_used_at"), now=now, ttl_hours=ttl_hours
         )
@@ -452,6 +714,8 @@ def audit_branches_directory(
             branch_gone=branch is None and not entry.get("detached"),
             ttl_expired=ttl_expired,
             is_protected=is_protected,
+            merged_pr_cleanup=merged_pr_cleanup,
+            has_live_session=has_live_session,
         )
         metadata["cleanup_eligibility"] = classification
         worktrees.append(
@@ -463,7 +727,10 @@ def audit_branches_directory(
                 "has_open_pr": has_open_pr,
                 "has_active_lease": has_active_lease,
                 "has_active_issue_lock": has_active_lock,
+                "has_live_session": has_live_session,
                 "is_protected": is_protected,
+                "merged_pr_linkage": linkage,
+                "merged_pr_cleanup": merged_pr_cleanup,
                 "classification": classification,
                 "removable": is_removable(classification),
             }