Merge remote-tracking branch 'prgs/master' into feat/issue-639-webui-system-health-dashboard

Resolve the #638 shell landing against the #639 dashboard:

- webui/layout.py: drop the flat NAV_ITEMS tuple in favor of master's
  grouped NAV_GROUPS nav-config module.
- webui/nav.py: register /system-health as a live item in the Health
  group, satisfying issue #639 AC5 through the canonical nav source.
- docs/webui-local-dev.md: keep both additive sections (#638 shell and
  #639 dashboard).
- tests/test_webui_system_health_dashboard.py: assert the nav entry via
  iter_nav_items() instead of the removed NAV_ITEMS tuple.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

canonical_thread_handoff.py

@@ -46,6 +46,17 @@ _FIELD_RE = re.compile(
 )
 
 
+def is_known_cth_type(value: str | None) -> bool:
+    """True when *value* is a declared member of the :data:`CTH_TYPES` contract.
+
+    ``CTH_TYPES`` is the single authority for what a CTH type may be. The
+    heading a comment carries is free text, so a *read* path that turns a parsed
+    type into something durable — a serialized field, a routing decision — must
+    check membership here rather than trust the parse or keep a list of its own.
+    """
+    return (value or "").strip() in CTH_TYPES
+
+
 def format_cth_body(
     *,
     cth_type: str,
@@ -60,7 +71,7 @@ def format_cth_body(
 ) -> str:
     """Render a canonical CTH comment body."""
     normalized_type = (cth_type or "").strip()
-    if normalized_type not in CTH_TYPES:
+    if not is_known_cth_type(normalized_type):
         raise ValueError(
             f"unknown CTH type '{cth_type}'; expected one of {sorted(CTH_TYPES)}"
         )
@@ -101,6 +112,12 @@ def parse_cth_comment(body: str) -> dict[str, Any] | None:
         fields[key] = match.group(2).strip()
     return {
         "cth_type": cth_type,
+        # The heading capture is unconstrained free text, so the parse states
+        # whether it satisfies the CTH_TYPES contract instead of leaving every
+        # reader to decide (or forget). Parsing stays total — an unknown type is
+        # still parsed and reported, never raised on — but a reader that turns
+        # the type into a durable value can now tell the two apart.
+        "cth_type_known": is_known_cth_type(cth_type),
         "fields": fields,
         "raw_body": text,
     }
@@ -119,7 +136,7 @@ def assess_cth_comment(body: str) -> dict[str, Any]:
         }
 
     cth_type = parsed.get("cth_type") or ""
-    if cth_type not in CTH_TYPES:
+    if not is_known_cth_type(cth_type):
         reasons.append(
             f"unknown CTH type '{cth_type}'; expected one of {sorted(CTH_TYPES)}"
         )

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**
@@ -317,6 +349,108 @@ health, workflow/schema SHA-256 hashes, and stale-runtime warnings when the
 checkout is behind merged safety-gate changes. Restart guidance links to #420;
 no tokens or MCP restart actions are exposed.
 
+## Workflow-event timeline (#637)
+
+`GET /api/v1/timeline` is a read-only, versioned aggregation of workflow
+events from every available source into one normalised, filterable stream. It
+is the model layer for the Phase 1 timeline console view (a later child issue
+of #631); this issue ships the schema, adapters, and read API only.
+
+### Schema (versioned)
+
+`webui/timeline.py` declares `TIMELINE_SCHEMA_VERSION` (currently `1`) and the
+frozen `WorkflowEvent` record. Every response carries `schema_version` so a
+consumer can branch on shape. One event:
+
+```json
+{
+  "source": "control_plane",
+  "event_type": "lease.renew",
+  "event_key": "cp:1421",
+  "timestamp": "2026-07-23T02:00:00Z",
+  "actor": null,
+  "role": null,
+  "issue_number": 637,
+  "pr_number": null,
+  "session_id": null,
+  "tool_name": null,
+  "decision": null,
+  "message": "lease renewed",
+  "correlation_id": "issue#637",
+  "evidence_refs": [],
+  "sensitive": true
+}
+```
+
+`event_key` is stable and unique per source (`cp:<event_id>`,
+`cth:<kind>:<number>:<comment_id>`), so pagination and dedup are deterministic.
+
+### Sources and field authority
+
+| Source | Adapter | Authority |
+|---|---|---|
+| Control-plane `events` ⋈ `work_items` | `adapt_cp_events` | `event_type`, `message`, `timestamp`, issue/PR scope come from the CP database, read through a `mode=ro` URI (never creates the DB or runs migrations) |
+| Gitea Canonical Thread Handoff comments | `adapt_cth_comments` | `actor`, `role` (next owner), `decision`, `evidence_refs`, `timestamp` come from the parsed CTH comment body (`canonical_thread_handoff`) |
+
+Handoff comments are thread-scoped: they are only read when the request filters
+by a single `issue` or `pr`. Otherwise the handoff source reports `not run`
+with a reason — it is never rendered as empty-and-healthy. Each source degrades
+independently: an unavailable control-plane DB or a failed comment fetch is a
+`sources[]` entry with `ok:false` and a `reason`, never a dropped timeline.
+
+### Query parameters
+
+`issue`, `pr`, `session` (conjunctive filters); `limit` (default 50, max 500)
+and `offset` for pagination; `remote`, `org`, `repo` to override the default
+registry-project scope. Events sort ascending by
+`(timestamp, source_rank, event_key)`; missing timestamps sort last.
+
+### Filter authority, and refusing what cannot be answered
+
+A filter dimension is only meaningful for a source whose records carry it.
+Each source declares its own support in `_SOURCE_FILTER_SUPPORT` and reports it
+per response as `supported_filters` / `unsupported_filters`:
+
+| Source | issue | pr | session |
+|---|---|---|---|
+| `control_plane` | yes | yes | **no** — the `events` table is `(event_id, work_item_id, event_type, message, created_at)` and records no session |
+| `gitea_handoff` | yes | yes | yes — a CTH comment declares its own `Session:` field |
+
+`session_id` is read only from that declared CTH field. It is never inferred
+from a work item, an actor, or message text, and a value that is
+redaction-altering or bare-secret-shaped is dropped rather than emitted.
+
+When **no source that ran** can carry a requested dimension, the request is
+refused rather than answered: the response is `422` with `ok:false` and a
+structured `error` naming `unsupported_filters` and the per-source reason. A
+`200` with zero events would tell an operator that no such activity exists,
+which is a stronger — and false — claim than "this cannot be answered here".
+A source that *can* answer the dimension and simply matched nothing still
+returns `200` with `ok:true` and an empty page.
+
+### Redaction
+
+Every free-text field (event messages, decision/proof text, roles, actors) is
+passed through the console redaction policy (`webui.console_redaction`, backed
+by `gitea_audit.redact`) before it leaves the module, failing closed to the
+placeholder. No unredacted tool arguments or secrets are ever emitted, and a
+generation error never drops raw data to a caller or a log.
+
+Redaction also runs *before* any structured value is derived from free text.
+`evidence_refs` are extracted from already-redacted proof/decision text, and a
+commit reference is recognised only where the text declares one (`commit`,
+`head`, `base`, `sha`, …). An undeclared 40-character hex run has the exact
+shape of a Gitea access token, so it is never lifted out of prose into a
+structured field. Every reference is then independently revalidated against an
+allowed shape and a second redaction pass immediately before serialization;
+anything unproven is dropped and the event is flagged `sensitive`.
+
+### Tests
+
+```bash
+pytest tests/test_webui_timeline.py -q
+```
+
 ## Tests
 
 ```bash

gitea_mcp_server.py

@@ -11242,127 +11242,163 @@ def gitea_reconcile_merged_cleanups(
     if dry_run:
         report["dry_run"] = True
         report["executed"] = False
+        # #851: surface planned lifecycle order so dry-run matches execute.
+        report["planned_execution_orders"] = {
+            str(entry.get("pr_number")): entry.get("planned_execution_order") or []
+            for entry in (report.get("entries") or [])
+        }
         return {"success": True, "performed": False, **report}
 
     verify_preflight_purity(
         remote, task="reconcile_merged_cleanups", org=org, repo=repo
     )
     actions: list[dict] = []
+    project_root = _canonical_local_git_root()
+
+    def _ownership_records_for_branch(
+        head_branch: str, pr_num_int: int | None
+    ) -> list[dict]:
+        ownership_bundle = _collect_branch_ownership_records(
+            remote=remote,
+            host=h,
+            org=o,
+            repo=r,
+            branch=head_branch,
+            pr_number=pr_num_int,
+            project_root=project_root,
+            auth=auth,
+            base_api=base,
+        )
+        ownership_records = list(ownership_bundle.get("records") or [])
+        if ownership_bundle.get("inventory_error"):
+            ownership_records.append(
+                {
+                    "category": (
+                        branch_cleanup_guard.OWNERSHIP_CATEGORY_INVENTORY_ERROR
+                    ),
+                    "status": "unknown",
+                    "remote": remote,
+                    "host": h,
+                    "org": o,
+                    "repo": r,
+                    "branch": head_branch,
+                    "reclaim_allowed": False,
+                    "role": "inventory",
+                }
+            )
+        return ownership_records
+
+    def _attempt_owned_remote_delete(
+        *,
+        head_branch: str,
+        pr_num_int: int | None,
+        after_worktree_removal: bool = False,
+    ) -> dict:
+        """Fail-closed remote delete with live ownership reassessment (#851)."""
+        import urllib.parse
+
+        ownership_records = _ownership_records_for_branch(head_branch, pr_num_int)
+        ownership = branch_cleanup_guard.assess_active_branch_ownership(
+            remote=remote,
+            org=o,
+            repo=r,
+            branch=head_branch,
+            host=h,
+            records=ownership_records,
+        )
+        if ownership.get("block"):
+            return {
+                "action": "delete_remote_branch",
+                "branch": head_branch,
+                "success": False,
+                "performed": False,
+                "delete_acknowledged": False,
+                "verified_absent": False,
+                "blocker_kind": "active_branch_ownership",
+                "reasons": ownership.get("reasons") or [],
+                "blocking_categories": ownership.get("blocking_categories") or [],
+                "after_worktree_removal": after_worktree_removal,
+                "ownership_reassessed": after_worktree_removal,
+            }
+
+        encoded = urllib.parse.quote(head_branch, safe="")
+        url = f"{base}/branches/{encoded}"
+        with _audited(
+            "delete_branch",
+            host=h,
+            remote=remote,
+            org=o,
+            repo=r,
+            target_branch=head_branch,
+            request_metadata={
+                "branch": head_branch,
+                "source": "reconcile_merged_cleanups",
+                "ownership_checked": True,
+                "after_worktree_removal": after_worktree_removal,
+            },
+        ):
+            api_request("DELETE", url, auth)
+        readback = _probe_remote_branch(h, o, r, auth, head_branch)
+        readback_assessment = branch_cleanup_guard.assess_post_delete_readback(
+            readback
+        )
+        verified = bool(readback_assessment.get("verified_absent"))
+        return {
+            "action": "delete_remote_branch",
+            "branch": head_branch,
+            "success": bool(readback_assessment.get("ok")),
+            "performed": True,
+            "delete_acknowledged": True,
+            "verified_absent": verified,
+            "readback": readback_assessment.get("readback"),
+            "reasons": readback_assessment.get("reasons") or [],
+            "after_worktree_removal": after_worktree_removal,
+            "ownership_reassessed": after_worktree_removal,
+        }
+
     for entry in report.get("entries") or []:
         head_branch = entry.get("head_branch") or ""
         remote_assessment = entry.get("remote_branch") or {}
         local_assessment = entry.get("local_worktree") or {}
+        pr_num = entry.get("pr_number")
+        try:
+            pr_num_int = int(pr_num) if pr_num is not None else None
+        except (TypeError, ValueError):
+            pr_num_int = None
 
-        if remote_assessment.get("safe_to_delete_remote"):
+        # #851 lifecycle: when the target worktree is independently safe, remove
-            import urllib.parse
+        # it first so worktree_binding ownership does not permanently strand
-
+        # both the worktree and the remote branch. Never skip worktree removal
-            pr_num = entry.get("pr_number")
+        # merely because remote delete would be blocked by that binding.
-            try:
+        # Ownership protection for remote delete remains fail-closed below.
-                pr_num_int = int(pr_num) if pr_num is not None else None
+        worktree_removed = False
-            except (TypeError, ValueError):
-                pr_num_int = None
-            ownership_bundle = _collect_branch_ownership_records(
-                remote=remote,
-                host=h,
-                org=o,
-                repo=r,
-                branch=head_branch,
-                pr_number=pr_num_int,
-                project_root=_canonical_local_git_root(),
-                auth=auth,
-                base_api=base,
-            )
-            ownership_records = list(ownership_bundle.get("records") or [])
-            if ownership_bundle.get("inventory_error"):
-                ownership_records.append(
-                    {
-                        "category": (
-                            branch_cleanup_guard.OWNERSHIP_CATEGORY_INVENTORY_ERROR
-                        ),
-                        "status": "unknown",
-                        "remote": remote,
-                        "host": h,
-                        "org": o,
-                        "repo": r,
-                        "branch": head_branch,
-                        "reclaim_allowed": False,
-                        "role": "inventory",
-                    }
-                )
-            ownership = branch_cleanup_guard.assess_active_branch_ownership(
-                remote=remote,
-                org=o,
-                repo=r,
-                branch=head_branch,
-                host=h,
-                records=ownership_records,
-            )
-            if ownership.get("block"):
-                actions.append(
-                    {
-                        "action": "delete_remote_branch",
-                        "branch": head_branch,
-                        "success": False,
-                        "performed": False,
-                        "delete_acknowledged": False,
-                        "verified_absent": False,
-                        "blocker_kind": "active_branch_ownership",
-                        "reasons": ownership.get("reasons") or [],
-                        "blocking_categories": ownership.get(
-                            "blocking_categories"
-                        )
-                        or [],
-                    }
-                )
-                continue
-
-            encoded = urllib.parse.quote(head_branch, safe="")
-            url = f"{base}/branches/{encoded}"
-            with _audited(
-                "delete_branch",
-                host=h,
-                remote=remote,
-                org=o,
-                repo=r,
-                target_branch=head_branch,
-                request_metadata={
-                    "branch": head_branch,
-                    "source": "reconcile_merged_cleanups",
-                    "ownership_checked": True,
-                },
-            ):
-                api_request("DELETE", url, auth)
-            readback = _probe_remote_branch(h, o, r, auth, head_branch)
-            readback_assessment = branch_cleanup_guard.assess_post_delete_readback(
-                readback
-            )
-            verified = bool(readback_assessment.get("verified_absent"))
-            actions.append(
-                {
-                    "action": "delete_remote_branch",
-                    "branch": head_branch,
-                    "success": bool(readback_assessment.get("ok")),
-                    "performed": True,
-                    "delete_acknowledged": True,
-                    "verified_absent": verified,
-                    "readback": readback_assessment.get("readback"),
-                    "reasons": readback_assessment.get("reasons") or [],
-                }
-            )
-
         if local_assessment.get("safe_to_remove_worktree"):
             result = merged_cleanup_reconcile.remove_local_worktree(
-                _canonical_local_git_root(),
+                project_root,
                 head_branch,
                 worktree_path=local_assessment.get("worktree_path"),
             )
             actions.append({"action": "remove_local_worktree", **result})
+            # Idempotent resume: absent worktree is already gone.
+            msg = (result.get("message") or "").lower()
+            worktree_removed = bool(result.get("success")) or (
+                "not found" in msg
+            )
+
+        if remote_assessment.get("safe_to_delete_remote"):
+            actions.append(
+                _attempt_owned_remote_delete(
+                    head_branch=head_branch,
+                    pr_num_int=pr_num_int,
+                    after_worktree_removal=worktree_removed,
+                )
+            )
 
     for scratch in report.get("reviewer_scratch_entries") or []:
         if not scratch.get("safe_to_remove_worktree"):
             continue
         result = merged_cleanup_reconcile.remove_reviewer_scratch_worktree(
-            _canonical_local_git_root(), scratch.get("worktree_path") or ""
+            project_root, scratch.get("worktree_path") or ""
         )
         actions.append({"action": "remove_reviewer_scratch_worktree", **result})
 

merged_cleanup_reconcile.py

@@ -566,6 +566,10 @@ def build_pr_cleanup_entry(
         worktree_state=worktree_state,
         active_lock=active_lock,
     )
+    planned = plan_cleanup_execution_order(
+        remote_assessment=remote,
+        local_assessment=local,
+    )
     return {
         "pr_number": pr_number,
         "issue_number": issue_number,
@@ -576,9 +580,63 @@ def build_pr_cleanup_entry(
         "merged": merged,
         "remote_branch": remote,
         "local_worktree": local,
+        # #851: dry-run and execute share the same lifecycle order description.
+        "planned_execution_order": planned,
     }
 
 
+def plan_cleanup_execution_order(
+    *,
+    remote_assessment: dict[str, Any] | None,
+    local_assessment: dict[str, Any] | None,
+) -> list[dict[str, Any]]:
+    """Describe independent worktree-then-reassess-then-remote cleanup order (#851).
+
+    Remote ownership protection remains fail-closed at execute time. A worktree
+    that is independently safe to remove is never skipped merely because remote
+    deletion may be blocked by that same ``worktree_binding``.
+    """
+    remote = remote_assessment or {}
+    local = local_assessment or {}
+    steps: list[dict[str, Any]] = []
+    worktree_safe = bool(local.get("safe_to_remove_worktree"))
+    remote_safe = bool(remote.get("safe_to_delete_remote"))
+
+    if worktree_safe:
+        steps.append(
+            {
+                "action": "remove_local_worktree",
+                "reason": "independently_safe_to_remove",
+                "phase": 1,
+            }
+        )
+    if remote_safe:
+        if worktree_safe:
+            steps.append(
+                {
+                    "action": "reassess_branch_ownership",
+                    "reason": "after_worktree_removal_clear_worktree_binding",
+                    "phase": 2,
+                }
+            )
+            steps.append(
+                {
+                    "action": "delete_remote_branch",
+                    "reason": "only_if_independently_safe_after_reassessment",
+                    "phase": 3,
+                }
+            )
+        else:
+            steps.append(
+                {
+                    "action": "delete_remote_branch",
+                    "reason": "safe_to_delete_and_no_independent_worktree_removal",
+                    "phase": 1,
+                }
+            )
+    return steps
+
+
 def build_reconciliation_report(
     *,
     project_root: str,

tests/test_branch_cleanup_guard.py

@@ -1266,6 +1266,378 @@ class TestSecondRemediationIntegration(unittest.TestCase):
         self.assertIn("delete_acknowledged", delete_actions[0])
         self.assertTrue(delete_actions[0].get("verified_absent"))
 
+    def test_issue_851_worktree_removed_when_remote_blocked_only_by_worktree_binding(self):
+        """#851: remote blocked by worktree_binding must not skip safe worktree removal.
+
+        Lifecycle: remove clean owned worktree → reassess ownership → delete
+        remote only if independently safe. Unrelated entries stay untouched.
+        """
+        from mcp_server import gitea_reconcile_merged_cleanups
+
+        target_branch = "fix/issue-844-exclude-epic-containers"
+        foreign_branch = "fix/issue-999-unrelated-active"
+        worktree_path = "/tmp/branches/fix-issue-844-exclude-epic-containers"
+        ownership_calls = []
+        remove_calls = []
+        delete_api_calls = []
+
+        def fake_collect(**kwargs):
+            ownership_calls.append(dict(kwargs))
+            # Ownership is reassessed *after* independent worktree removal (#851).
+            # Target worktree is already gone → no worktree_binding remains.
+            # Foreign branch keeps an active author lease → remote delete blocked.
+            if kwargs.get("branch") == foreign_branch:
+                # Match session-bound org/repo + host used by the tool resolve path.
+                return {
+                    "records": [
+                        {
+                            "category": guard.OWNERSHIP_CATEGORY_AUTHOR_LEASE,
+                            "status": "active",
+                            "remote": kwargs.get("remote") or "prgs",
+                            "host": kwargs.get("host") or "gitea.example.com",
+                            "org": kwargs.get("org") or "Scaled-Tech-Consulting",
+                            "repo": kwargs.get("repo") or "Gitea-Tools",
+                            "branch": foreign_branch,
+                            "reclaim_allowed": False,
+                        }
+                    ],
+                    "inventory_error": False,
+                }
+            return {"records": [], "inventory_error": False}
+
+        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 {worktree_path}",
+                "worktree_path": worktree_path,
+            }
+
+        def fake_probe(h, o, r, auth, br):
+            return guard.classify_branch_readback_http_status(
+                404, not_found_scope=guard.NOT_FOUND_SCOPE_BRANCH
+            )
+
+        def fake_api(method, url, auth, **kwargs):
+            if method == "DELETE":
+                delete_api_calls.append(url)
+            return {}
+
+        report = {
+            "entries": [
+                {
+                    "pr_number": 848,
+                    "head_branch": target_branch,
+                    "remote_branch": {"safe_to_delete_remote": True},
+                    "local_worktree": {
+                        "safe_to_remove_worktree": True,
+                        "worktree_path": worktree_path,
+                    },
+                },
+                {
+                    "pr_number": 999,
+                    "head_branch": foreign_branch,
+                    "remote_branch": {"safe_to_delete_remote": True},
+                    "local_worktree": {
+                        "safe_to_remove_worktree": False,
+                        "worktree_path": None,
+                    },
+                },
+            ],
+            "reviewer_scratch_entries": [],
+        }
+        patch(
+            "mcp_server.get_profile",
+            return_value={
+                "profile_name": "prgs-reconciler",
+                "role": "reconciler",
+                "allowed_operations": [
+                    "gitea.read",
+                    "gitea.branch.delete",
+                    "gitea.pr.close",
+                ],
+                "forbidden_operations": [],
+            },
+        ).start()
+        patch("mcp_server.api_get_all", return_value=[]).start()
+        patch(
+            "mcp_server.merged_cleanup_reconcile.build_reconciliation_report",
+            return_value=report,
+        ).start()
+        patch(
+            "mcp_server.merged_cleanup_reconcile.discover_reviewer_scratch_worktrees",
+            return_value=[],
+        ).start()
+        patch(
+            "mcp_server.audit_reconciliation_mode.check_cleanup_execution_allowed",
+            return_value=(True, []),
+        ).start()
+        patch("mcp_server.verify_preflight_purity", return_value=None).start()
+        patch(
+            "mcp_server._collect_branch_ownership_records",
+            side_effect=fake_collect,
+        ).start()
+        patch("mcp_server._probe_remote_branch", side_effect=fake_probe).start()
+        patch(
+            "mcp_server.merged_cleanup_reconcile.remove_local_worktree",
+            side_effect=fake_remove,
+        ).start()
+        self.mock_api.side_effect = fake_api
+
+        res = gitea_reconcile_merged_cleanups(
+            dry_run=False,
+            execute_confirmed=True,
+            remote="prgs",
+        )
+        self.assertTrue(res.get("performed") or res.get("executed"))
+        actions = res.get("actions") or []
+
+        remove_actions = [
+            a for a in actions if a.get("action") == "remove_local_worktree"
+        ]
+        self.assertEqual(len(remove_actions), 1, actions)
+        self.assertTrue(remove_actions[0].get("success"))
+        self.assertEqual(remove_calls[0]["branch"], target_branch)
+        self.assertEqual(remove_calls[0]["worktree_path"], worktree_path)
+
+        # Target remote delete succeeds after worktree removal + reassessment.
+        target_deletes = [
+            a
+            for a in actions
+            if a.get("action") == "delete_remote_branch"
+            and a.get("branch") == target_branch
+        ]
+        self.assertEqual(len(target_deletes), 1, actions)
+        self.assertTrue(target_deletes[0].get("success"))
+        self.assertTrue(target_deletes[0].get("after_worktree_removal"))
+        self.assertTrue(target_deletes[0].get("ownership_reassessed"))
+        self.assertTrue(target_deletes[0].get("verified_absent"))
+
+        # Foreign branch remains protected (author lease) and is not deleted.
+        foreign_deletes = [
+            a
+            for a in actions
+            if a.get("action") == "delete_remote_branch"
+            and a.get("branch") == foreign_branch
+        ]
+        self.assertEqual(len(foreign_deletes), 1, actions)
+        self.assertFalse(foreign_deletes[0].get("success"))
+        self.assertEqual(
+            foreign_deletes[0].get("blocker_kind"), "active_branch_ownership"
+        )
+        self.assertIn(
+            guard.OWNERSHIP_CATEGORY_AUTHOR_LEASE,
+            foreign_deletes[0].get("blocking_categories") or [],
+        )
+        # Only the target branch should hit the DELETE API.
+        self.assertEqual(len(delete_api_calls), 1)
+
+        # Ownership collected for target (post-removal) and foreign; worktree
+        # removal happened before target remote delete in the action log.
+        target_idx = next(
+            i
+            for i, a in enumerate(actions)
+            if a.get("action") == "remove_local_worktree"
+        )
+        delete_idx = next(
+            i
+            for i, a in enumerate(actions)
+            if a.get("action") == "delete_remote_branch"
+            and a.get("branch") == target_branch
+            and a.get("success")
+        )
+        self.assertLess(target_idx, delete_idx)
+
+    def test_issue_851_dirty_worktree_not_removed_and_remote_stays_protected(self):
+        """#851: dirty/foreign worktrees remain protected; no unsafe cleanup."""
+        from mcp_server import gitea_reconcile_merged_cleanups
+
+        branch = "fix/issue-851-dirty"
+        remove_calls = []
+
+        def fake_collect(**kwargs):
+            return {
+                "records": [
+                    {
+                        "category": guard.OWNERSHIP_CATEGORY_WORKTREE_BINDING,
+                        "status": "active",
+                        "remote": kwargs.get("remote") or "prgs",
+                        "host": kwargs.get("host") or "gitea.example.com",
+                        "org": kwargs.get("org") or "Scaled-Tech-Consulting",
+                        "repo": kwargs.get("repo") or "Gitea-Tools",
+                        "branch": branch,
+                        "reclaim_allowed": False,
+                    }
+                ],
+                "inventory_error": False,
+            }
+
+        report = {
+            "entries": [
+                {
+                    "pr_number": 851,
+                    "head_branch": branch,
+                    "remote_branch": {"safe_to_delete_remote": True},
+                    "local_worktree": {
+                        "safe_to_remove_worktree": False,
+                        "worktree_path": "/tmp/dirty-wt",
+                    },
+                }
+            ],
+            "reviewer_scratch_entries": [],
+        }
+        patch(
+            "mcp_server.get_profile",
+            return_value={
+                "profile_name": "prgs-reconciler",
+                "role": "reconciler",
+                "allowed_operations": [
+                    "gitea.read",
+                    "gitea.branch.delete",
+                ],
+                "forbidden_operations": [],
+            },
+        ).start()
+        patch("mcp_server.api_get_all", return_value=[]).start()
+        patch(
+            "mcp_server.merged_cleanup_reconcile.build_reconciliation_report",
+            return_value=report,
+        ).start()
+        patch(
+            "mcp_server.merged_cleanup_reconcile.discover_reviewer_scratch_worktrees",
+            return_value=[],
+        ).start()
+        patch(
+            "mcp_server.audit_reconciliation_mode.check_cleanup_execution_allowed",
+            return_value=(True, []),
+        ).start()
+        patch("mcp_server.verify_preflight_purity", return_value=None).start()
+        patch(
+            "mcp_server._collect_branch_ownership_records",
+            side_effect=fake_collect,
+        ).start()
+        patch(
+            "mcp_server.merged_cleanup_reconcile.remove_local_worktree",
+            side_effect=lambda *a, **k: remove_calls.append(k) or {
+                "success": True,
+                "performed": True,
+            },
+        ).start()
+        self.mock_api.side_effect = lambda *a, **k: {}
+
+        res = gitea_reconcile_merged_cleanups(
+            dry_run=False,
+            execute_confirmed=True,
+            remote="prgs",
+        )
+        actions = res.get("actions") or []
+        self.assertEqual(remove_calls, [])
+        self.assertFalse(
+            any(a.get("action") == "remove_local_worktree" for a in actions)
+        )
+        deletes = [
+            a for a in actions if a.get("action") == "delete_remote_branch"
+        ]
+        self.assertEqual(len(deletes), 1)
+        self.assertFalse(deletes[0].get("success"))
+        self.assertEqual(deletes[0].get("blocker_kind"), "active_branch_ownership")
+        self.assertIn(
+            guard.OWNERSHIP_CATEGORY_WORKTREE_BINDING,
+            deletes[0].get("blocking_categories") or [],
+        )
+
+    def test_issue_851_idempotent_resume_when_worktree_already_absent(self):
+        """#851: partial failures remain resumable and idempotent."""
+        from mcp_server import gitea_reconcile_merged_cleanups
+
+        branch = "fix/issue-851-resume"
+        ownership_calls = []
+
+        def fake_collect(**kwargs):
+            ownership_calls.append(kwargs)
+            return {"records": [], "inventory_error": False}
+
+        def fake_remove(project_root, branch, worktree_path=None):
+            return {
+                "success": False,
+                "performed": False,
+                "message": f"worktree not found: {worktree_path}",
+            }
+
+        def fake_probe(h, o, r, auth, br):
+            return guard.classify_branch_readback_http_status(
+                404, not_found_scope=guard.NOT_FOUND_SCOPE_BRANCH
+            )
+
+        report = {
+            "entries": [
+                {
+                    "pr_number": 851,
+                    "head_branch": branch,
+                    "remote_branch": {"safe_to_delete_remote": True},
+                    "local_worktree": {
+                        "safe_to_remove_worktree": True,
+                        "worktree_path": "/tmp/already-gone",
+                    },
+                }
+            ],
+            "reviewer_scratch_entries": [],
+        }
+        patch(
+            "mcp_server.get_profile",
+            return_value={
+                "profile_name": "prgs-reconciler",
+                "role": "reconciler",
+                "allowed_operations": [
+                    "gitea.read",
+                    "gitea.branch.delete",
+                ],
+                "forbidden_operations": [],
+            },
+        ).start()
+        patch("mcp_server.api_get_all", return_value=[]).start()
+        patch(
+            "mcp_server.merged_cleanup_reconcile.build_reconciliation_report",
+            return_value=report,
+        ).start()
+        patch(
+            "mcp_server.merged_cleanup_reconcile.discover_reviewer_scratch_worktrees",
+            return_value=[],
+        ).start()
+        patch(
+            "mcp_server.audit_reconciliation_mode.check_cleanup_execution_allowed",
+            return_value=(True, []),
+        ).start()
+        patch("mcp_server.verify_preflight_purity", return_value=None).start()
+        patch(
+            "mcp_server._collect_branch_ownership_records",
+            side_effect=fake_collect,
+        ).start()
+        patch("mcp_server._probe_remote_branch", side_effect=fake_probe).start()
+        patch(
+            "mcp_server.merged_cleanup_reconcile.remove_local_worktree",
+            side_effect=fake_remove,
+        ).start()
+        self.mock_api.side_effect = lambda *a, **k: {}
+
+        res = gitea_reconcile_merged_cleanups(
+            dry_run=False,
+            execute_confirmed=True,
+            remote="prgs",
+        )
+        actions = res.get("actions") or []
+        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.assertFalse(removes[0].get("success"))
+        self.assertEqual(len(deletes), 1)
+        self.assertTrue(deletes[0].get("success"))
+        self.assertTrue(deletes[0].get("after_worktree_removal"))
+        self.assertTrue(ownership_calls)
+
 
 
 if __name__ == "__main__":

tests/test_merged_cleanup_reconcile.py

@@ -12,6 +12,59 @@ import merged_cleanup_reconcile as mcr  # noqa: E402
 
 
 class TestMergedCleanupAssessment(unittest.TestCase):
+    def test_issue_851_plan_order_worktree_then_reassess_then_remote(self):
+        """#851 dry-run plan: remove worktree, reassess ownership, then remote."""
+        plan = mcr.plan_cleanup_execution_order(
+            remote_assessment={"safe_to_delete_remote": True},
+            local_assessment={"safe_to_remove_worktree": True},
+        )
+        actions = [s["action"] for s in plan]
+        self.assertEqual(
+            actions,
+            [
+                "remove_local_worktree",
+                "reassess_branch_ownership",
+                "delete_remote_branch",
+            ],
+        )
+        self.assertEqual(plan[0]["phase"], 1)
+        self.assertEqual(plan[-1]["phase"], 3)
+        self.assertIn("independently_safe", plan[0]["reason"])
+        self.assertIn("reassessment", plan[-1]["reason"])
+
+    def test_issue_851_plan_remote_only_when_worktree_not_safe(self):
+        plan = mcr.plan_cleanup_execution_order(
+            remote_assessment={"safe_to_delete_remote": True},
+            local_assessment={"safe_to_remove_worktree": False},
+        )
+        self.assertEqual([s["action"] for s in plan], ["delete_remote_branch"])
+        self.assertNotIn("reassess_branch_ownership", [s["action"] for s in plan])
+
+    def test_issue_851_plan_worktree_only_when_remote_not_safe(self):
+        plan = mcr.plan_cleanup_execution_order(
+            remote_assessment={"safe_to_delete_remote": False},
+            local_assessment={"safe_to_remove_worktree": True},
+        )
+        self.assertEqual([s["action"] for s in plan], ["remove_local_worktree"])
+
+    def test_issue_851_entry_includes_planned_execution_order(self):
+        entry = mcr.build_pr_cleanup_entry(
+            pr={
+                "number": 848,
+                "title": "Closes #844",
+                "body": "",
+                "merged_at": "2026-07-23T00:00:00Z",
+                "head": {"ref": "fix/issue-844-x", "sha": "a" * 40},
+            },
+            project_root="/tmp/not-a-real-root",
+            open_pr_heads=set(),
+            remote_branch_exists=True,
+            head_on_master=True,
+            delete_capability_allowed=True,
+        )
+        self.assertIn("planned_execution_order", entry)
+        self.assertIsInstance(entry["planned_execution_order"], list)
+
     def test_extract_linked_issue_from_closes(self):
         issue = mcr.extract_linked_issue(
             "feat: cleanup (Closes #269)",

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()

webui/app.py

@@ -46,12 +46,14 @@ from webui.worktree_scanner import load_hygiene_snapshot, snapshot_to_dict as wo
 from webui.worktree_views import render_worktrees_page
 from webui.runtime_health import load_runtime_snapshot, snapshot_to_dict as runtime_snapshot_to_dict
 from webui.runtime_views import render_runtime_page
+from webui.timeline import load_timeline, snapshot_to_dict as timeline_snapshot_to_dict
 from webui.system_health import (
     API_PATH as SYSTEM_HEALTH_API_PATH,
     load_system_health,
     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"})
@@ -160,6 +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)))
@@ -449,6 +469,104 @@ async def api_console_security_model(_request: Request) -> JSONResponse:
     })
 
 
+def _query_int(request: Request, key: str) -> int | None:
+    """Parse an optional integer query parameter; None when absent/invalid."""
+    raw = request.query_params.get(key)
+    if raw is None or not str(raw).strip():
+        return None
+    try:
+        return int(str(raw).strip())
+    except (TypeError, ValueError):
+        return None
+
+
+def _derive_remote(host: str) -> str:
+    """Map a Gitea host to its known short remote name (control-plane scope key)."""
+    text = (host or "").lower()
+    if "prgs" in text:
+        return "prgs"
+    if "dadeschools" in text:
+        return "dadeschools"
+    return text.split(".")[0] if text else ""
+
+
+def _timeline_comment_source(host: str, org: str, repo: str):
+    """Build a fail-soft CTH-comment fetcher for one repo, or None when offline.
+
+    Returns a callable ``(kind, number) -> list[comment]``. Credentials or
+    network failures raise inside the callable so ``load_timeline`` degrades the
+    handoff source rather than the whole timeline. Offline test mode yields no
+    live source so the handoff section reports ``not run``.
+    """
+    import os
+
+    from gitea_auth import api_fetch_page, get_auth_header, repo_api_url
+
+    offline = (os.environ.get("WEBUI_TEST_OFFLINE") or "").strip().lower() in {"1", "true", "yes"}
+    if offline:
+        return None
+    auth = get_auth_header(host)
+    if not auth:
+        return None
+
+    def _fetch(kind: str, number: int) -> list:
+        segment = "pulls" if kind == "pr" else "issues"
+        url = f"{repo_api_url(host, org, repo)}/{segment}/{int(number)}/comments"
+        comments: list = []
+        page = 1
+        while page <= 20:
+            raw, meta = api_fetch_page(url, auth, page=page, limit=50)
+            comments.extend(raw)
+            if bool(meta["is_final_page"]):
+                break
+            page += 1
+        return comments
+
+    return _fetch
+
+
+async def api_v1_timeline(request: Request) -> JSONResponse:
+    """Read-only workflow-event timeline (#637). Filter by issue/PR/session."""
+    from webui.queue_loader import _host_from_url  # host normalisation helper
+
+    registry, error = _load_project_registry()
+    if error is not None:
+        return JSONResponse(error.to_dict(), status_code=500)
+    project = registry.projects[0] if registry.projects else None
+
+    org = request.query_params.get("org") or (project.gitea_owner if project else "")
+    repo = request.query_params.get("repo") or (project.repo_name if project else "")
+    host = _host_from_url(project.remote_host) if project else ""
+    remote = request.query_params.get("remote") or _derive_remote(host)
+
+    if not (remote and org and repo):
+        return JSONResponse(
+            {
+                "error": "timeline_scope_unresolved",
+                "detail": "no project in registry and no remote/org/repo query params provided",
+            },
+            status_code=400,
+        )
+
+    comment_source = _timeline_comment_source(host, org, repo) if (host and org and repo) else None
+
+    snapshot = load_timeline(
+        remote=remote,
+        org=org,
+        repo=repo,
+        issue=_query_int(request, "issue"),
+        pr=_query_int(request, "pr"),
+        session=(request.query_params.get("session") or None),
+        limit=_query_int(request, "limit"),
+        offset=_query_int(request, "offset"),
+        comment_source=comment_source,
+    )
+    # A filter no surviving source can carry is refused, not answered empty:
+    # a 200 with zero events would tell the operator no such activity exists.
+    status_code = 200 if snapshot.ok else 422
+    return JSONResponse(timeline_snapshot_to_dict(snapshot), status_code=status_code)
+
+
 async def method_not_allowed(request: Request, _exc: Exception) -> Response:
     path = request.url.path
     if path in _AUDIT_MUTATION_PATHS and request.method == "POST":
@@ -472,6 +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"]),
@@ -488,6 +607,7 @@ def create_app(*, bind_host: str | None = None) -> Starlette:
             Route("/api/prompts", api_prompts, methods=["GET"]),
             Route("/runtime", runtime, methods=["GET"]),
             Route("/api/runtime", api_runtime, methods=["GET"]),
+            Route("/api/v1/timeline", api_v1_timeline, methods=["GET"]),
             Route("/audit", audit, methods=["GET", "POST"]),
             Route("/api/audit", api_audit, methods=["GET", "POST"]),
             Route("/worktrees", worktrees, 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()}"
+    )

webui/timeline.py

@@ -0,0 +1,906 @@
+"""Workflow-event and conversation timeline model (#637, Phase 1).
+
+Operators cannot browse a unified timeline of workflow events, decisions,
+tool calls, and handoffs: the evidence is scattered across control-plane
+events, Gitea canonical handoff comments, and local logs. This module defines
+one durable, versioned event schema and per-source adapters that normalise
+those scattered records into a single ``WorkflowEvent`` stream, plus a
+read-only query layer (filter by issue / PR / session, stable ordering,
+pagination) that the ``/api/v1/timeline`` route serves.
+
+Design rules honoured here:
+
+- **Read-only.** Sources are read; nothing is mutated. The control-plane
+  database is opened through a ``mode=ro`` URI so a missing or unwritable DB
+  degrades to a reason instead of creating directories or running migrations.
+- **Fail-soft per source.** An unavailable source degrades to a status with a
+  reason rather than raising, and a source that could not run is never
+  rendered as an empty-and-healthy timeline.
+- **Answerable filters only.** Each source declares which filter dimensions it
+  can actually answer. A filter dimension no source that ran can carry is
+  refused with an explicit reason rather than silently matching nothing: an
+  empty page from an unanswerable filter reads to an operator as "no such
+  activity", which is a different — and false — statement.
+- **Redaction at the boundary, fail closed.** Every free-text field (event
+  messages, redacted tool arguments, decision/proof text) is run through the
+  console redaction policy before it leaves this module, and *before* any
+  structured value is derived from it — evidence references are extracted from
+  redacted text, then independently revalidated before serialization. An
+  unredactable value becomes the placeholder, and a value that cannot be proven
+  safe is dropped — an unredacted payload is never emitted, and a generation
+  error never drops raw data to a caller or a log.
+- **Stable ordering.** Events sort by ``(timestamp, source_rank, event_key)``
+  with a deterministic tiebreak, so pagination is stable across calls and
+  events with equal or missing timestamps keep a fixed order.
+
+Non-goals (from the issue): no full chat replay, no mutation of historical
+events, no unredacted tool-argument storage.
+"""
+
+from __future__ import annotations
+
+import re
+import sqlite3
+from dataclasses import dataclass, replace
+from datetime import datetime, timezone
+from typing import Any, Callable, Iterable
+
+import control_plane_db
+from webui import console_redaction
+
+# The schema is versioned so consumers can branch on shape. Bump on any
+# breaking change to WorkflowEvent's serialized form.
+TIMELINE_SCHEMA_VERSION = 1
+
+# Known event sources and their deterministic ordering rank. When two events
+# carry the same timestamp, the source rank breaks the tie before the
+# per-source event key, so a control-plane event and a handoff comment minted
+# in the same second always sort in a fixed order.
+SOURCE_CONTROL_PLANE = "control_plane"
+SOURCE_GITEA_HANDOFF = "gitea_handoff"
+_SOURCE_RANK = {
+    SOURCE_CONTROL_PLANE: 0,
+    SOURCE_GITEA_HANDOFF: 1,
+}
+
+# The filter dimensions the query layer accepts.
+FILTER_ISSUE = "issue"
+FILTER_PR = "pr"
+FILTER_SESSION = "session"
+
+# Which dimensions each source can actually answer. This is a property of the
+# underlying records, not of the query code: the control-plane ``events`` table
+# is (event_id, work_item_id, event_type, message, created_at) and carries no
+# session identity at all, so no control-plane event can ever match a session
+# filter. A CTH handoff comment can declare its session as a field, so the
+# handoff source answers all three. Filtering on a dimension the surviving
+# sources cannot carry is refused in ``load_timeline`` rather than answered
+# with an empty page.
+_SOURCE_FILTER_SUPPORT: dict[str, tuple[str, ...]] = {
+    SOURCE_CONTROL_PLANE: (FILTER_ISSUE, FILTER_PR),
+    SOURCE_GITEA_HANDOFF: (FILTER_ISSUE, FILTER_PR, FILTER_SESSION),
+}
+
+# Why a source cannot answer a dimension, for the refusal reason an operator reads.
+_SOURCE_FILTER_LIMITS: dict[tuple[str, str], str] = {
+    (SOURCE_CONTROL_PLANE, FILTER_SESSION): (
+        "control-plane events carry no session identity "
+        "(the events table has no session column)"
+    ),
+}
+
+# A timestamp far in the future so events with no parseable timestamp sort
+# last (after everything real) instead of first, without raising.
+_MISSING_TS_SORT = "9999-12-31T23:59:59Z"
+
+
+def _parse_ts(value: str | None) -> str | None:
+    """Normalise a timestamp to ``...Z`` UTC, or None when unparseable."""
+    if not value:
+        return None
+    text = str(value).strip()
+    if not text:
+        return None
+    candidate = text[:-1] + "+00:00" if text.endswith("Z") else text
+    try:
+        parsed = datetime.fromisoformat(candidate)
+    except ValueError:
+        return None
+    if parsed.tzinfo is None:
+        parsed = parsed.replace(tzinfo=timezone.utc)
+    return parsed.astimezone(timezone.utc).replace(microsecond=0).isoformat().replace("+00:00", "Z")
+
+
+def _redact(value: Any) -> Any:
+    """Redact a single free-text field, failing closed to the placeholder."""
+    if value is None:
+        return None
+    return console_redaction.redact_text(str(value))
+
+
+@dataclass(frozen=True)
+class WorkflowEvent:
+    """One normalised timeline event.
+
+    Every field is optional except ``source``/``event_type``/``event_key``
+    because sources carry different subsets. The class is frozen so an adapted
+    event is an immutable record; a consumer that needs a variant builds a new
+    one rather than mutating history.
+    """
+
+    source: str
+    event_type: str
+    event_key: str
+    timestamp: str | None = None
+    actor: str | None = None
+    role: str | None = None
+    issue_number: int | None = None
+    pr_number: int | None = None
+    session_id: str | None = None
+    tool_name: str | None = None
+    decision: str | None = None
+    message: str | None = None
+    correlation_id: str | None = None
+    evidence_refs: tuple[str, ...] = ()
+    sensitive: bool = False
+
+    def sort_key(self) -> tuple[str, int, str]:
+        return (
+            self.timestamp or _MISSING_TS_SORT,
+            _SOURCE_RANK.get(self.source, 99),
+            self.event_key,
+        )
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "source": self.source,
+            "event_type": self.event_type,
+            "event_key": self.event_key,
+            "timestamp": self.timestamp,
+            "actor": self.actor,
+            "role": self.role,
+            "issue_number": self.issue_number,
+            "pr_number": self.pr_number,
+            "session_id": self.session_id,
+            "tool_name": self.tool_name,
+            "decision": self.decision,
+            "message": self.message,
+            "correlation_id": self.correlation_id,
+            "evidence_refs": list(self.evidence_refs),
+            "sensitive": self.sensitive,
+        }
+
+
+# --------------------------------------------------------------------------- #
+# Adapters — pure functions from a source's raw records to WorkflowEvents.     #
+# Each is total: a malformed record is skipped, never raised on.               #
+# --------------------------------------------------------------------------- #
+
+# Event types whose payload is treated as sensitive and always redaction-hard
+# (they can carry lease/session provenance or tool arguments).
+_SENSITIVE_EVENT_HINTS = ("lease", "capability", "token", "auth", "secret")
+
+# Reference tokens (issue/PR/comment ids) and SHAs parsed out of proof text.
+_EVIDENCE_REF_RE = re.compile(r"(?:#|PR\s*#?|issue\s*#?|comment\s*#?)(\d+)", re.IGNORECASE)
+
+# A commit reference is only recognised when the text *declares* it as one.
+# A bare lowercase hex run is not evidence of anything: at 40 characters it is
+# exactly the shape of a Gitea personal access token, and at 7 it also matches
+# ordinary words such as "defaced". Requiring an anchoring keyword keeps real
+# references ("commit abc1234", "at head a209756...", "base caaae9b6") usable
+# while refusing to lift an undeclared secret-shaped run out of free text.
+_SHA_RE = re.compile(
+    r"(?i:\b(?:commit|sha|head|base|parent|revision|rev|merge[- ]base)\b[\s:=@#]*)"
+    r"([0-9a-f]{7,40})\b"
+)
+
+# Shapes a serialized evidence reference is allowed to take. Anything else is
+# dropped rather than emitted.
+_REF_ISSUE_SHAPE = re.compile(r"^#[0-9]{1,9}$")
+_REF_SHA_SHAPE = re.compile(r"^[0-9a-f]{7,40}$")
+
+# A long undelimited hex run with no declaring context is treated as credential
+# material wherever it appears, never as an identifier.
+_BARE_SECRET_SHAPE = re.compile(r"^[0-9a-f]{32,}$")
+
+# An event type reads like an identifier, but a stored one is externally
+# influenced: any producer that writes the control-plane ``events`` table
+# chooses the string. It reaches ``to_dict`` verbatim, so it is validated here
+# rather than trusted because of where it came from.
+_CP_EVENT_TYPE_SHAPE = re.compile(r"^[A-Za-z][A-Za-z0-9._:+-]{0,63}$")
+
+# Emitted in place of a value that cannot be proven safe. Deliberately not a
+# plausible workflow type: an unsafe value is refused, never quietly rewritten
+# into a different valid-looking one that would misdescribe the record.
+UNSAFE_EVENT_TYPE = "unsafe:redacted"
+
+# Emitted for a CTH heading that is not a declared member of ``CTH_TYPES``. The
+# contract is enforced on write (``format_cth_body``) and on assess; the read
+# path the timeline uses enforces it too rather than assuming it was.
+UNKNOWN_HANDOFF_EVENT_TYPE = "handoff:unrecognized"
+
+# A source record id is a plain integer in both sources it comes from: the
+# control-plane ``events`` primary key and a Gitea comment id. ``event_key`` is
+# serialized verbatim and is the pagination tiebreak, so anything else is
+# refused rather than interpolated into it.
+_RECORD_ID_SHAPE = re.compile(r"^[0-9]{1,19}$")
+
+
+def _kind_to_numbers(kind: str | None, number: int | None) -> tuple[int | None, int | None]:
+    """Map a control-plane work-item (kind, number) to (issue_no, pr_no)."""
+    if number is None:
+        return (None, None)
+    if kind == "pr":
+        return (None, int(number))
+    if kind == "issue":
+        return (int(number), None)
+    return (None, None)
+
+
+def _correlation_for(kind: str | None, number: int | None) -> str | None:
+    if number is None or kind not in ("issue", "pr"):
+        return None
+    return f"{kind}#{number}"
+
+
+def _extract_evidence_refs(*texts: str | None) -> tuple[str, ...]:
+    """Extract issue/PR and declared-commit references from **redacted** text.
+
+    Callers must pass text that has already been through :func:`_redact`; this
+    function derives a structured field from its input, so extracting ahead of
+    redaction would republish whatever redaction was about to remove. Every
+    reference is revalidated by :func:`_validated_evidence_refs` before it is
+    serialized.
+    """
+    refs: list[str] = []
+    for text in texts:
+        if not text:
+            continue
+        for match in _EVIDENCE_REF_RE.finditer(text):
+            token = f"#{match.group(1)}"
+            if token not in refs:
+                refs.append(token)
+        for match in _SHA_RE.finditer(text):
+            token = match.group(1)
+            if token not in refs:
+                refs.append(token)
+    return tuple(refs)
+
+
+def _validated_evidence_refs(refs: Iterable[str]) -> tuple[tuple[str, ...], bool]:
+    """Independently revalidate references immediately before serialization.
+
+    Extraction is not trusted on its own. A reference survives only when it has
+    a known reference shape and is unchanged by a second redaction pass — a
+    value the redaction policy would alter is credential material that must not
+    be emitted as a structured field. A full 40-character SHA stays usable
+    because extraction only accepts a hex run the source text explicitly
+    declared as a commit. Returns ``(safe_refs, dropped_any)``; ``dropped_any``
+    marks the event sensitive so the drop is visible rather than silent.
+    """
+    safe: list[str] = []
+    dropped = False
+    for ref in refs or ():
+        try:
+            token = str(ref).strip()
+            if not token:
+                continue
+            recognised = bool(_REF_ISSUE_SHAPE.match(token) or _REF_SHA_SHAPE.match(token))
+            if not recognised:
+                dropped = True
+                continue
+            if _redact(token) != token:
+                dropped = True
+                continue
+            if token not in safe:
+                safe.append(token)
+        except Exception:
+            # Fail closed: a reference that cannot be proven safe is dropped.
+            dropped = True
+            continue
+    return (tuple(safe), dropped)
+
+
+def _safe_session_id(value: Any) -> str | None:
+    """Return a session identifier only when it is safe to emit.
+
+    The value is authoritative source data — a session the record names for
+    itself — but it is still free text. It is dropped when redaction alters it
+    or when it is a bare secret-shaped hex run, so a credential parked in a
+    session field can never reach the payload or be echoed back by a filter.
+    """
+    if value is None:
+        return None
+    text = str(value).strip()
+    if not text:
+        return None
+    if _BARE_SECRET_SHAPE.match(text):
+        return None
+    return text if _redact(text) == text else None
+
+
+def _safe_record_id(value: Any) -> str | None:
+    """Return a source record id only when it is a plain numeric identifier.
+
+    ``event_key`` is serialized verbatim and is the deterministic pagination
+    tiebreak, so an id is interpolated into it only when it has the shape both
+    real sources actually produce. A record whose identity cannot be trusted is
+    refused by the caller rather than keyed on.
+    """
+    if value is None or isinstance(value, bool):
+        return None
+    if isinstance(value, int):
+        return str(value)
+    text = str(value).strip()
+    return text if _RECORD_ID_SHAPE.match(text) else None
+
+
+def _safe_cp_event_type(value: Any) -> tuple[str, bool]:
+    """Validate a stored control-plane event type. Returns ``(type, unsafe)``.
+
+    The stored value is externally influenced — whichever producer wrote the
+    ``events`` row chose the string — and ``to_dict`` serializes it verbatim, so
+    it passes a boundary of its own instead of relying on the one ``message``
+    passes. A value survives only when it is an ordinary identifier, is not a
+    bare secret-shaped hex run, and is unchanged by a redaction pass. Anything
+    else fails closed to :data:`UNSAFE_EVENT_TYPE`: the record stays visible as
+    an audit entry, but the value itself is never republished — not verbatim,
+    not partially sanitized, and not rewritten into some other valid-looking
+    type that would misdescribe what happened.
+    """
+    text = ("" if value is None else str(value)).strip()
+    if not text:
+        return ("", False)
+    if _BARE_SECRET_SHAPE.match(text):
+        return (UNSAFE_EVENT_TYPE, True)
+    if not _CP_EVENT_TYPE_SHAPE.match(text):
+        return (UNSAFE_EVENT_TYPE, True)
+    if _redact(text) != text:
+        return (UNSAFE_EVENT_TYPE, True)
+    return (text, False)
+
+
+def _safe_echo(value: Any) -> Any:
+    """Guard a scalar that is echoed back rather than derived from a record.
+
+    Query scope and filter values are caller-supplied and are reflected in the
+    response so an operator can see what was asked. Reflection is still
+    emission: a value redaction would alter, or a bare secret-shaped hex run, is
+    replaced by the placeholder instead of being echoed verbatim. Ordinary
+    scope and filter values pass through untouched.
+    """
+    if value is None or isinstance(value, (int, bool)):
+        return value
+    text = str(value)
+    if _BARE_SECRET_SHAPE.match(text.strip()):
+        return console_redaction.REDACTED
+    return _redact(text)
+
+
+def adapt_cp_events(rows: Iterable[dict[str, Any]]) -> list[WorkflowEvent]:
+    """Adapt control-plane ``events`` rows (joined to work_items) into events.
+
+    Each row is expected to carry ``event_id``, ``event_type``, ``message``,
+    ``created_at`` and the joined work-item ``kind``/``number``. Rows missing
+    an id or type are skipped so a partially written table never raises.
+    """
+    events: list[WorkflowEvent] = []
+    for row in rows or []:
+        try:
+            event_id = _safe_record_id(row.get("event_id"))
+            raw_event_type = (row.get("event_type") or "").strip()
+            if event_id is None or not raw_event_type:
+                continue
+            # The stored type is source data, not a trusted constant: validate
+            # it before it is serialized, exactly as `message` below is redacted
+            # before it is serialized.
+            event_type, event_type_unsafe = _safe_cp_event_type(raw_event_type)
+            kind = row.get("kind")
+            number = row.get("number")
+            issue_no, pr_no = _kind_to_numbers(kind, number)
+            sensitive = event_type_unsafe or any(
+                hint in raw_event_type.lower() for hint in _SENSITIVE_EVENT_HINTS
+            )
+            events.append(
+                WorkflowEvent(
+                    source=SOURCE_CONTROL_PLANE,
+                    event_type=event_type,
+                    event_key=f"cp:{event_id}",
+                    timestamp=_parse_ts(row.get("created_at")),
+                    issue_number=issue_no,
+                    pr_number=pr_no,
+                    # No session_id: the control-plane events table is
+                    # (event_id, work_item_id, event_type, message, created_at)
+                    # and records no session. Inventing one from the work item
+                    # or the message text would be a guess, so this source
+                    # declares the session dimension unsupported instead
+                    # (_SOURCE_FILTER_SUPPORT) and the query layer refuses a
+                    # session filter it cannot honestly answer.
+                    message=_redact(row.get("message")),
+                    correlation_id=_correlation_for(kind, number),
+                    sensitive=sensitive,
+                )
+            )
+        except Exception:
+            # A single malformed row must not sink the whole adaptation.
+            continue
+    return events
+
+
+def adapt_cth_comments(
+    comments: Iterable[dict[str, Any]],
+    *,
+    kind: str,
+    number: int,
+) -> list[WorkflowEvent]:
+    """Adapt Gitea Canonical Thread Handoff (CTH) comments into events.
+
+    Only comments that parse as a CTH (``canonical_thread_handoff.parse_cth_comment``)
+    become events; ordinary comments are ignored. ``kind``/``number`` scope the
+    events to the issue or PR the comments belong to.
+    """
+    # Imported lazily so this module has no import-time dependency on the
+    # handoff parser when only the control-plane adapter is used.
+    from canonical_thread_handoff import is_known_cth_type, parse_cth_comment
+
+    # ``kind``/``number`` are interpolated into event_key and correlation_id, so
+    # they are normalised once here. A scope this adapter cannot express is
+    # refused outright rather than serialized into an identifier.
+    kind = (kind or "").strip().lower()
+    if kind not in ("issue", "pr"):
+        return []
+    try:
+        number = int(number)
+    except (TypeError, ValueError):
+        return []
+
+    issue_no, pr_no = _kind_to_numbers(kind, number)
+    correlation = _correlation_for(kind, number)
+    events: list[WorkflowEvent] = []
+    for comment in comments or []:
+        try:
+            body = comment.get("body") or ""
+            parsed = parse_cth_comment(body)
+            if not parsed:
+                continue
+            fields = parsed.get("fields") or {}
+            cth_type = parsed.get("cth_type") or ""
+            comment_id = _safe_record_id(comment.get("id"))
+            if comment_id is None:
+                continue
+            # The CTH heading is free text: the parser accepts whatever follows
+            # "## CTH:", and only the write and assess paths check it against
+            # the contract. Check it here too — an unrecognised heading is
+            # reported as such rather than serialized into event_type, so
+            # arbitrary, malformed, or secret-shaped heading content has no way
+            # through. Declared types are preserved exactly.
+            cth_type_known = is_known_cth_type(cth_type)
+            # Redaction runs first, and every derived value is taken from the
+            # redacted text — deriving evidence refs from the raw proof would
+            # re-emit exactly what redaction was about to remove.
+            decision = _redact(fields.get("decision"))
+            proof = _redact(fields.get("proof"))
+            next_action = _redact(fields.get("next action"))
+            refs, refs_dropped = _validated_evidence_refs(
+                _extract_evidence_refs(proof, decision)
+            )
+            events.append(
+                WorkflowEvent(
+                    source=SOURCE_GITEA_HANDOFF,
+                    event_type=(
+                        f"handoff:{cth_type.strip()}"
+                        if cth_type_known
+                        else UNKNOWN_HANDOFF_EVENT_TYPE
+                    ),
+                    event_key=f"cth:{kind}:{number}:{comment_id}",
+                    timestamp=_parse_ts(comment.get("created_at")),
+                    actor=_redact((comment.get("user") or {}).get("login")),
+                    role=_redact(fields.get("next owner")),
+                    issue_number=issue_no,
+                    pr_number=pr_no,
+                    # A CTH names its own session when the producer records one;
+                    # it is read from that declared field, never inferred from
+                    # unrelated text.
+                    session_id=_safe_session_id(fields.get("session")),
+                    decision=decision,
+                    message=next_action or _redact(fields.get("status")),
+                    correlation_id=correlation,
+                    evidence_refs=refs,
+                    sensitive=refs_dropped or not cth_type_known,
+                )
+            )
+        except Exception:
+            continue
+    return events
+
+
+# --------------------------------------------------------------------------- #
+# Read-only control-plane event source.                                       #
+# --------------------------------------------------------------------------- #
+
+_CP_EVENTS_QUERY = """
+SELECT e.event_id   AS event_id,
+       e.event_type AS event_type,
+       e.message    AS message,
+       e.created_at AS created_at,
+       w.kind       AS kind,
+       w.number     AS number
+FROM events e
+JOIN work_items w ON e.work_item_id = w.work_item_id
+WHERE w.remote = ? AND w.org = ? AND w.repo = ?
+"""
+
+
+@dataclass(frozen=True)
+class SourceStatus:
+    """Fail-soft status for one timeline source.
+
+    ``supported_filters`` states which filter dimensions this source's records
+    can carry; ``unsupported_filters`` names the requested dimensions it cannot,
+    so an operator can see *why* a source contributed nothing rather than being
+    left to read an empty list as an absence of activity.
+    """
+
+    name: str
+    ok: bool
+    reason: str | None = None
+    count: int = 0
+    supported_filters: tuple[str, ...] = ()
+    unsupported_filters: tuple[str, ...] = ()
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "name": self.name,
+            "ok": self.ok,
+            "reason": self.reason,
+            "count": self.count,
+            "supported_filters": list(self.supported_filters),
+            "unsupported_filters": list(self.unsupported_filters),
+        }
+
+
+def _cp_status(*, ok: bool, reason: str | None = None, count: int = 0) -> SourceStatus:
+    return SourceStatus(
+        SOURCE_CONTROL_PLANE,
+        ok=ok,
+        # A failure reason is serialized like any other field and is often an
+        # exception string carrying a path or a transport error, so it crosses
+        # the redaction boundary too. Static reasons pass through unchanged.
+        reason=_redact(reason),
+        count=count,
+        supported_filters=_SOURCE_FILTER_SUPPORT[SOURCE_CONTROL_PLANE],
+    )
+
+
+def _handoff_status(*, ok: bool, reason: str | None = None, count: int = 0) -> SourceStatus:
+    return SourceStatus(
+        SOURCE_GITEA_HANDOFF,
+        ok=ok,
+        # Same boundary as the control-plane status: this reason can quote an
+        # error raised by a live authenticated fetch.
+        reason=_redact(reason),
+        count=count,
+        supported_filters=_SOURCE_FILTER_SUPPORT[SOURCE_GITEA_HANDOFF],
+    )
+
+
+def read_cp_events(
+    *,
+    remote: str,
+    org: str,
+    repo: str,
+    db_path: str | None = None,
+) -> tuple[list[WorkflowEvent], SourceStatus]:
+    """Read scoped control-plane events read-only. Never creates the DB.
+
+    Opens the SQLite file through a ``mode=ro`` URI: a health/timeline read
+    must never create directories or run the schema migration that
+    ``ControlPlaneDB()`` performs on construction. A missing or unreadable DB
+    degrades to a status with a reason.
+    """
+    path = (db_path or control_plane_db.default_db_path()).strip()
+    conn: sqlite3.Connection | None = None
+    try:
+        conn = sqlite3.connect(f"file:{path}?mode=ro", uri=True)
+        conn.row_factory = sqlite3.Row
+        cursor = conn.execute(_CP_EVENTS_QUERY, (remote, org, repo))
+        rows = [dict(r) for r in cursor.fetchall()]
+    except sqlite3.OperationalError as exc:
+        return ([], _cp_status(ok=False, reason=f"control-plane DB unavailable: {exc}"))
+    except sqlite3.Error as exc:
+        return ([], _cp_status(ok=False, reason=f"control-plane read failed: {exc}"))
+    finally:
+        if conn is not None:
+            conn.close()
+    events = adapt_cp_events(rows)
+    return (events, _cp_status(ok=True, count=len(events)))
+
+
+# --------------------------------------------------------------------------- #
+# Filter, sort, paginate.                                                     #
+# --------------------------------------------------------------------------- #
+
+
+def filter_events(
+    events: Iterable[WorkflowEvent],
+    *,
+    issue: int | None = None,
+    pr: int | None = None,
+    session: str | None = None,
+) -> list[WorkflowEvent]:
+    """Filter events by issue number, PR number, and/or session id.
+
+    Filters are conjunctive. A filter that names a dimension an event does not
+    carry excludes that event (an issue filter excludes PR-only events).
+    """
+    out: list[WorkflowEvent] = []
+    for ev in events:
+        if issue is not None and ev.issue_number != issue:
+            continue
+        if pr is not None and ev.pr_number != pr:
+            continue
+        if session is not None and ev.session_id != session:
+            continue
+        out.append(ev)
+    return out
+
+
+def sort_events(events: Iterable[WorkflowEvent]) -> list[WorkflowEvent]:
+    """Return events in stable timeline order (ascending)."""
+    return sorted(events, key=lambda ev: ev.sort_key())
+
+
+@dataclass(frozen=True)
+class TimelinePage:
+    """One page of the sorted, filtered timeline."""
+
+    events: tuple[WorkflowEvent, ...]
+    total: int
+    limit: int
+    offset: int
+
+    @property
+    def next_offset(self) -> int | None:
+        nxt = self.offset + len(self.events)
+        return nxt if nxt < self.total else None
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "events": [ev.to_dict() for ev in self.events],
+            "pagination": {
+                "total": self.total,
+                "limit": self.limit,
+                "offset": self.offset,
+                "returned": len(self.events),
+                "next_offset": self.next_offset,
+                "has_more": self.next_offset is not None,
+            },
+        }
+
+
+_MAX_LIMIT = 500
+_DEFAULT_LIMIT = 50
+
+
+def _coerce_bounds(limit: int | None, offset: int | None) -> tuple[int, int]:
+    try:
+        lim = int(limit) if limit is not None else _DEFAULT_LIMIT
+    except (TypeError, ValueError):
+        lim = _DEFAULT_LIMIT
+    try:
+        off = int(offset) if offset is not None else 0
+    except (TypeError, ValueError):
+        off = 0
+    lim = max(1, min(lim, _MAX_LIMIT))
+    off = max(0, off)
+    return (lim, off)
+
+
+def paginate(events: list[WorkflowEvent], *, limit: int | None, offset: int | None) -> TimelinePage:
+    lim, off = _coerce_bounds(limit, offset)
+    window = events[off : off + lim]
+    return TimelinePage(events=tuple(window), total=len(events), limit=lim, offset=off)
+
+
+# --------------------------------------------------------------------------- #
+# Composition — load_timeline aggregates all sources, fail-soft.              #
+# --------------------------------------------------------------------------- #
+
+# A comment source is a callable that, given (kind, number), returns the raw
+# Gitea comment list for that issue/PR. The route supplies a live fail-soft
+# fetcher; tests supply a fixture. When None, the handoff source is reported as
+# not-run (never silently empty-and-healthy).
+CommentSource = Callable[[str, int], list[dict[str, Any]]]
+
+
+@dataclass(frozen=True)
+class TimelineSnapshot:
+    """One answered timeline query.
+
+    ``ok`` is False when the query could not be answered as asked — currently
+    when a requested filter dimension no surviving source can carry was
+    supplied. The page is then empty *and* the snapshot says so, because an
+    ``ok`` empty page is a claim that no such activity exists.
+    """
+
+    schema_version: int
+    remote: str
+    org: str
+    repo: str
+    filters: dict[str, Any]
+    page: TimelinePage
+    sources: tuple[SourceStatus, ...]
+    ok: bool = True
+    error: dict[str, Any] | None = None
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "ok": self.ok,
+            "error": self.error,
+            "schema_version": self.schema_version,
+            # Scope and filters are echoed caller input, not derived record
+            # data. Reflecting a value is still emitting it, so both cross the
+            # same boundary; ordinary scope and filter values are unchanged.
+            "scope": {
+                "remote": _safe_echo(self.remote),
+                "org": _safe_echo(self.org),
+                "repo": _safe_echo(self.repo),
+            },
+            "filters": {key: _safe_echo(value) for key, value in self.filters.items()},
+            "sources": [s.to_dict() for s in self.sources],
+            **self.page.to_dict(),
+        }
+
+
+def _unanswerable_reasons(
+    statuses: Iterable[SourceStatus], unanswerable: Iterable[str]
+) -> list[dict[str, str]]:
+    """Explain, per source, why each unanswerable dimension went unanswered."""
+    out: list[dict[str, str]] = []
+    for status in statuses:
+        for dim in unanswerable:
+            if dim not in status.supported_filters:
+                reason = _SOURCE_FILTER_LIMITS.get(
+                    (status.name, dim), f"this source's records carry no {dim} identity"
+                )
+            elif not status.ok:
+                reason = (
+                    f"this source can carry {dim} but did not run: "
+                    f"{status.reason or 'unavailable'}"
+                )
+            else:
+                continue
+            out.append({"source": status.name, "filter": dim, "reason": reason})
+    return out
+
+
+def load_timeline(
+    *,
+    remote: str,
+    org: str,
+    repo: str,
+    issue: int | None = None,
+    pr: int | None = None,
+    session: str | None = None,
+    limit: int | None = None,
+    offset: int | None = None,
+    db_path: str | None = None,
+    comment_source: CommentSource | None = None,
+) -> TimelineSnapshot:
+    """Aggregate every timeline source into one filtered, paginated snapshot.
+
+    Sources are read independently and fail soft: an unavailable source
+    contributes a ``SourceStatus`` with ``ok=False`` and a reason, and never
+    collapses the whole timeline. The handoff source only runs when a specific
+    issue or PR is requested (a handoff comment belongs to one thread) and a
+    ``comment_source`` is available; otherwise it is reported as ``not run``
+    rather than as an empty-and-healthy source.
+
+    A filter dimension that no surviving source can carry — a ``session``
+    filter when the only source that ran is the control plane, whose events
+    record no session — is refused with ``ok=False`` and a structured error
+    instead of being answered with an empty page.
+    """
+    all_events: list[WorkflowEvent] = []
+    statuses: list[SourceStatus] = []
+
+    cp_events, cp_status = read_cp_events(remote=remote, org=org, repo=repo, db_path=db_path)
+    all_events.extend(cp_events)
+    statuses.append(cp_status)
+
+    # Gitea handoff comments are thread-scoped: only fetch when the caller
+    # narrowed to one issue or PR, and only when a source was provided.
+    handoff_target: tuple[str, int] | None = None
+    if pr is not None:
+        handoff_target = ("pr", pr)
+    elif issue is not None:
+        handoff_target = ("issue", issue)
+
+    if handoff_target is None:
+        statuses.append(
+            _handoff_status(
+                ok=False,
+                reason="not run: handoff comments are thread-scoped; filter by issue or pr to include them",
+            )
+        )
+    elif comment_source is None:
+        statuses.append(
+            _handoff_status(
+                ok=False,
+                reason="not run: no comment source configured for this timeline read",
+            )
+        )
+    else:
+        kind, number = handoff_target
+        try:
+            comments = comment_source(kind, number) or []
+            handoff_events = adapt_cth_comments(comments, kind=kind, number=number)
+            all_events.extend(handoff_events)
+            statuses.append(_handoff_status(ok=True, count=len(handoff_events)))
+        except Exception as exc:  # fail soft: a fetch/parse error degrades this source only
+            statuses.append(_handoff_status(ok=False, reason=f"handoff source failed: {exc}"))
+
+    requested = tuple(
+        name
+        for name, value in ((FILTER_ISSUE, issue), (FILTER_PR, pr), (FILTER_SESSION, session))
+        if value is not None
+    )
+    statuses = [
+        replace(
+            status,
+            unsupported_filters=tuple(
+                dim for dim in requested if dim not in status.supported_filters
+            ),
+        )
+        for status in statuses
+    ]
+    filters = {"issue": issue, "pr": pr, "session": session}
+
+    # A dimension is answerable only if a source that actually ran can carry it.
+    # If none can, refuse: an empty page would assert "no such activity", which
+    # is a claim this timeline is not in a position to make.
+    answerable: set[str] = set()
+    for status in statuses:
+        if status.ok:
+            answerable.update(status.supported_filters)
+    unanswerable = tuple(dim for dim in requested if dim not in answerable)
+
+    if unanswerable:
+        return TimelineSnapshot(
+            schema_version=TIMELINE_SCHEMA_VERSION,
+            remote=remote,
+            org=org,
+            repo=repo,
+            filters=filters,
+            page=paginate([], limit=limit, offset=offset),
+            sources=tuple(statuses),
+            ok=False,
+            error={
+                "code": "filter_not_supported",
+                "unsupported_filters": list(unanswerable),
+                "detail": (
+                    "no timeline source that ran can answer "
+                    + ", ".join(f"'{dim}'" for dim in unanswerable)
+                    + "; the result is refused rather than returned empty"
+                ),
+                "sources": _unanswerable_reasons(statuses, unanswerable),
+            },
+        )
+
+    filtered = filter_events(all_events, issue=issue, pr=pr, session=session)
+    ordered = sort_events(filtered)
+    page = paginate(ordered, limit=limit, offset=offset)
+
+    return TimelineSnapshot(
+        schema_version=TIMELINE_SCHEMA_VERSION,
+        remote=remote,
+        org=org,
+        repo=repo,
+        filters=filters,
+        page=page,
+        sources=tuple(statuses),
+    )
+
+
+def snapshot_to_dict(snapshot: TimelineSnapshot) -> dict[str, Any]:
+    return snapshot.to_dict()