Merge branch 'master' into feat/issue-628-autonomous-handoffs-orchestration

Reviewed-on: #876
Reviewed-by: sysadmin <[email protected]>

branch_cleanup_guard.py

@@ -163,7 +163,19 @@ _TERMINAL_OWNERSHIP_STATUSES = frozenset(
     {"released", "abandoned", "done", "blocked", "terminal", "closed"}
 )
 _EXPIRED_STATUSES = frozenset({"expired"})
-_STALE_STATUSES = frozenset({"stale", "stale_dead_process", "stale_missing_worktree"})
+_STALE_STATUSES = frozenset(
+    {
+        "stale",
+        "stale_dead_process",
+        "stale_missing_worktree",
+        # #790 Slice A heartbeat-lifecycle bands. Listed here so they are
+        # *classified* rather than falling through to the unknown-status branch;
+        # they still block unless the ownership record proves
+        # ``reclaim_allowed is True``, so the O2 fail-closed rule is unchanged.
+        "stale_missed_heartbeat",
+        "stale_absolute_cap",
+    }
+)
 
 
 def _norm_str(value: Any) -> str:

control_plane_db.py

@@ -31,7 +31,7 @@ from typing import Any, Iterator, Sequence
 
 import dependency_graph
 
-SCHEMA_VERSION = 4
+SCHEMA_VERSION = 5
 
 # Assignable work kinds only — raw monitoring incidents are never work items.
 WORK_KINDS = frozenset({"issue", "pr"})
@@ -186,6 +186,34 @@ CREATE INDEX IF NOT EXISTS idx_dependency_edges_target
     ON dependency_edges(remote, org, repo, target_kind, target_number);
 CREATE INDEX IF NOT EXISTS idx_assignments_session ON assignments(session_id, status);
 CREATE INDEX IF NOT EXISTS idx_incident_gitea ON incident_links(gitea_org, gitea_repo, gitea_issue_number);
+
+-- Model usage, token cost, latency, and performance events (#651)
+CREATE TABLE IF NOT EXISTS usage_events (
+    usage_id INTEGER PRIMARY KEY AUTOINCREMENT,
+    session_id TEXT,
+    remote TEXT NOT NULL DEFAULT 'dadeschools',
+    org TEXT NOT NULL DEFAULT '',
+    repo TEXT NOT NULL DEFAULT '',
+    project_id TEXT,
+    role TEXT NOT NULL DEFAULT 'unknown',
+    model TEXT NOT NULL DEFAULT 'unknown',
+    issue_number INTEGER,
+    pr_number INTEGER,
+    stage TEXT NOT NULL DEFAULT 'unknown',
+    input_tokens INTEGER,
+    output_tokens INTEGER,
+    total_tokens INTEGER,
+    estimated_cost_usd REAL,
+    latency_ms INTEGER,
+    duration_ms INTEGER,
+    status TEXT NOT NULL DEFAULT 'success',
+    metadata TEXT,
+    created_at TEXT NOT NULL
+);
+
+CREATE INDEX IF NOT EXISTS idx_usage_events_scope ON usage_events(remote, org, repo);
+CREATE INDEX IF NOT EXISTS idx_usage_events_role_model ON usage_events(role, model);
+CREATE INDEX IF NOT EXISTS idx_usage_events_stage ON usage_events(stage);
 """
 
 
@@ -339,6 +367,7 @@ class ControlPlaneDB:
                 self._migrate_incident_links_null_scope(conn)
                 self._migrate_lease_lifecycle_columns(conn)
                 self._migrate_session_ownership_columns(conn)
+                self._migrate_usage_events_table(conn)
                 conn.execute(
                     "INSERT OR REPLACE INTO schema_meta(key, value) VALUES (?, ?)",
                     ("schema_version", str(SCHEMA_VERSION)),
@@ -518,6 +547,207 @@ class ControlPlaneDB:
                     f"UPDATE incident_links SET {col} = '' WHERE {col} IS NULL"
                 )
 
+    def _migrate_usage_events_table(self, conn: sqlite3.Connection) -> None:
+        """Create usage_events table and indexes if they do not exist (#651)."""
+        conn.execute("""
+            CREATE TABLE IF NOT EXISTS usage_events (
+                usage_id INTEGER PRIMARY KEY AUTOINCREMENT,
+                session_id TEXT,
+                remote TEXT NOT NULL DEFAULT 'dadeschools',
+                org TEXT NOT NULL DEFAULT '',
+                repo TEXT NOT NULL DEFAULT '',
+                project_id TEXT,
+                role TEXT NOT NULL DEFAULT 'unknown',
+                model TEXT NOT NULL DEFAULT 'unknown',
+                issue_number INTEGER,
+                pr_number INTEGER,
+                stage TEXT NOT NULL DEFAULT 'unknown',
+                input_tokens INTEGER,
+                output_tokens INTEGER,
+                total_tokens INTEGER,
+                estimated_cost_usd REAL,
+                latency_ms INTEGER,
+                duration_ms INTEGER,
+                status TEXT NOT NULL DEFAULT 'success',
+                metadata TEXT,
+                created_at TEXT NOT NULL
+            );
+        """)
+        conn.execute("CREATE INDEX IF NOT EXISTS idx_usage_events_scope ON usage_events(remote, org, repo);")
+        conn.execute("CREATE INDEX IF NOT EXISTS idx_usage_events_role_model ON usage_events(role, model);")
+        conn.execute("CREATE INDEX IF NOT EXISTS idx_usage_events_stage ON usage_events(stage);")
+
+    # #651 retention: cap growth so unauthenticated or high-volume ingest
+    # cannot DoS the control-plane DB (PR #876 F3). Applied after every write.
+    USAGE_EVENTS_MAX_ROWS = 10_000
+    USAGE_EVENTS_RETENTION_DAYS = 90
+
+    def record_usage_event(
+        self,
+        *,
+        session_id: str | None = None,
+        remote: str = "dadeschools",
+        org: str = "",
+        repo: str = "",
+        project_id: str | None = None,
+        role: str = "unknown",
+        model: str = "unknown",
+        issue_number: int | None = None,
+        pr_number: int | None = None,
+        stage: str = "unknown",
+        input_tokens: int | None = None,
+        output_tokens: int | None = None,
+        total_tokens: int | None = None,
+        estimated_cost_usd: float | None = None,
+        latency_ms: int | None = None,
+        duration_ms: int | None = None,
+        status: str = "success",
+        metadata: str | dict[str, Any] | None = None,
+        created_at: str | None = None,
+    ) -> int:
+        """Record a model usage, token cost, latency, or stage performance event (#651)."""
+        ts = created_at or _ts()
+        meta_str: str | None = None
+        if metadata is not None:
+            from webui import console_redaction
+            redacted_meta = console_redaction.redact_payload(metadata)
+            if isinstance(redacted_meta, str):
+                meta_str = redacted_meta
+            else:
+                try:
+                    meta_str = json.dumps(redacted_meta, default=str)
+                except Exception:
+                    meta_str = str(redacted_meta)
+
+        if total_tokens is None and (input_tokens is not None or output_tokens is not None):
+            total_tokens = (input_tokens or 0) + (output_tokens or 0)
+
+        with self._tx(immediate=True) as conn:
+            cursor = conn.execute(
+                """
+                INSERT INTO usage_events (
+                    session_id, remote, org, repo, project_id, role, model,
+                    issue_number, pr_number, stage, input_tokens, output_tokens,
+                    total_tokens, estimated_cost_usd, latency_ms, duration_ms,
+                    status, metadata, created_at
+                ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+                """,
+                (
+                    session_id,
+                    remote,
+                    org,
+                    repo,
+                    project_id,
+                    role,
+                    model,
+                    issue_number,
+                    pr_number,
+                    stage,
+                    input_tokens,
+                    output_tokens,
+                    total_tokens,
+                    estimated_cost_usd,
+                    latency_ms,
+                    duration_ms,
+                    status,
+                    meta_str,
+                    ts,
+                ),
+            )
+            usage_id = cursor.lastrowid
+            self._enforce_usage_events_retention(conn)
+            return usage_id
+
+    def _enforce_usage_events_retention(self, conn: sqlite3.Connection) -> None:
+        """Drop aged and excess usage_events rows (PR #876 F3)."""
+        # Age-based: ISO-8601 UTC timestamps compare lexicographically.
+        cutoff = (
+            datetime.now(timezone.utc)
+            - timedelta(days=int(self.USAGE_EVENTS_RETENTION_DAYS))
+        ).strftime("%Y-%m-%dT%H:%M:%SZ")
+        conn.execute(
+            "DELETE FROM usage_events WHERE created_at < ?",
+            (cutoff,),
+        )
+        # Count-based: keep the newest USAGE_EVENTS_MAX_ROWS by usage_id.
+        max_rows = int(self.USAGE_EVENTS_MAX_ROWS)
+        if max_rows > 0:
+            conn.execute(
+                """
+                DELETE FROM usage_events
+                WHERE usage_id NOT IN (
+                    SELECT usage_id FROM usage_events
+                    ORDER BY usage_id DESC
+                    LIMIT ?
+                )
+                """,
+                (max_rows,),
+            )
+
+    def query_usage_events(
+        self,
+        *,
+        remote: str | None = None,
+        org: str | None = None,
+        repo: str | None = None,
+        project_id: str | None = None,
+        role: str | None = None,
+        model: str | None = None,
+        issue_number: int | None = None,
+        pr_number: int | None = None,
+        stage: str | None = None,
+        session_id: str | None = None,
+        limit: int = 500,
+        offset: int = 0,
+    ) -> list[dict[str, Any]]:
+        """Query stored usage events matching filters (#651)."""
+        conditions = []
+        params = []
+        if remote:
+            conditions.append("remote = ?")
+            params.append(remote)
+        if org:
+            conditions.append("org = ?")
+            params.append(org)
+        if repo:
+            conditions.append("repo = ?")
+            params.append(repo)
+        if project_id:
+            conditions.append("project_id = ?")
+            params.append(project_id)
+        if role:
+            conditions.append("role = ?")
+            params.append(role)
+        if model:
+            conditions.append("model = ?")
+            params.append(model)
+        if issue_number is not None:
+            conditions.append("issue_number = ?")
+            params.append(issue_number)
+        if pr_number is not None:
+            conditions.append("pr_number = ?")
+            params.append(pr_number)
+        if stage:
+            conditions.append("stage = ?")
+            params.append(stage)
+        if session_id:
+            conditions.append("session_id = ?")
+            params.append(session_id)
+
+        where_clause = f"WHERE {' AND '.join(conditions)}" if conditions else ""
+        sql = f"""
+            SELECT * FROM usage_events
+            {where_clause}
+            ORDER BY usage_id ASC
+            LIMIT ? OFFSET ?
+        """
+        params.extend([limit, offset])
+
+        with self._tx(immediate=False) as conn:
+            cursor = conn.execute(sql, params)
+            rows = cursor.fetchall()
+            return [dict(row) for row in rows]
+
     # ── sessions ──────────────────────────────────────────────────────────
 
     def upsert_session(

docs/mcp-tool-inventory.md

@@ -101,6 +101,7 @@ that gates each call, not which tools exist.
 - `gitea_get_profile`
 - `gitea_get_runtime_context`
 - `gitea_get_shell_health`
+- `gitea_heartbeat_issue_lock`
 - `gitea_heartbeat_reviewer_pr_lease`
 - `gitea_inspect_workflow_lease`
 - `gitea_issue_irrecoverable_provenance_authorization`

docs/observability/analytics-instrumentation.md

@@ -0,0 +1,143 @@
+# Model Usage, Token Cost, Latency, and Workflow Analytics (Phase 4)
+
+- **Tracking Issue:** [#651](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/651)
+- **Parent Epic:** [#631](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/651)
+- **Console Surface:** `/analytics`, `/api/v1/analytics`, `/api/v1/analytics/usage`
+
+## 1. Overview
+
+The Web Console Analytics module provides durable, aggregate visibility into **model usage, token cost, latency percentiles, and workflow-stage performance** across projects, worker roles, AI models, issues, and PRs.
+
+### Non-Goals
+- No mandatory client-side telemetry that leaks prompts or secret keys.
+- No third-party payment provider or billing integration.
+- No automatic model routing changes without controller policy (#647).
+
+---
+
+## 2. Event Schema (`usage_events`)
+
+Usage metrics are stored in the control-plane database under table `usage_events`.
+
+| Column | Type | Description |
+|---|---|---|
+| `usage_id` | `INTEGER` | Primary key (autoincrement) |
+| `session_id` | `TEXT` | Optional active session identifier |
+| `remote` | `TEXT` | Known Gitea instance (`dadeschools` or `prgs`) |
+| `org` | `TEXT` | Repository owner / organization |
+| `repo` | `TEXT` | Repository name |
+| `project_id` | `TEXT` | Optional project identifier |
+| `role` | `TEXT` | Active worker role (`author`, `reviewer`, `merger`, `reconciler`, `controller`) |
+| `model` | `TEXT` | LLM model identifier (e.g. `gemini-3.6-flash`, `claude-3-5-sonnet`) |
+| `issue_number` | `INTEGER` | Correlated Gitea issue number (optional) |
+| `pr_number` | `INTEGER` | Correlated Gitea PR number (optional) |
+| `stage` | `TEXT` | Workflow stage (`preflight`, `implementation`, `review`, `merge`, `reconciliation`) |
+| `input_tokens` | `INTEGER` | Input token count (optional / nullable) |
+| `output_tokens` | `INTEGER` | Output token count (optional / nullable) |
+| `total_tokens` | `INTEGER` | Total token count (optional / nullable) |
+| `estimated_cost_usd` | `REAL` | Estimated USD cost (optional / nullable) |
+| `latency_ms` | `INTEGER` | Request latency in milliseconds (optional / nullable) |
+| `duration_ms` | `INTEGER` | Stage execution duration in milliseconds (optional / nullable) |
+| `status` | `TEXT` | Outcome status (`success`, `failure`, `timeout`) |
+| `metadata` | `TEXT` | Redacted metadata or summary string |
+| `created_at` | `TEXT` | ISO 8601 UTC timestamp |
+
+---
+
+## 3. Handling of Missing Data ("Unknown" vs. Zero Fabrication)
+
+To ensure operational metrics accurately reflect evidence:
+- **Untracked or missing metrics are displayed as `Unknown`**, never zero-fabricated.
+- If an event omits `estimated_cost_usd`, `latency_ms`, or token counts, the aggregator marks those fields as missing (`None`) rather than defaulting to `0` or `$0.00`.
+- Summary tables and KPI cards explicitly indicate when data is unmeasured or partially reported.
+
+---
+
+## 4. Redaction & Security Rules
+
+Per `#633` security policy:
+- Free-text fields (`metadata`, `prompt_summary`, `session_id`) are run through `console_redaction.redact_text` before persistence and output serialization.
+- Secret tokens, keychain commands, authorization headers, passwords, and JWTs are stripped automatically.
+
+---
+
+## 5. Opt-in Instrumentation Guide
+
+Applications, MCP servers, and background sessions can report usage metrics through either Python API or HTTP ingestion.
+
+### Python Ingestion
+
+```python
+from webui.analytics_loader import record_usage
+
+record_usage(
+    remote="dadeschools",
+    org="Scaled-Tech-Consulting",
+    repo="Gitea-Tools",
+    role="author",
+    model="gemini-3.6-flash",
+    issue_number=651,
+    stage="implementation",
+    input_tokens=1420,
+    output_tokens=380,
+    total_tokens=1800,
+    estimated_cost_usd=0.00045,
+    latency_ms=320,
+    duration_ms=4500,
+    status="success",
+    metadata={"note": "Implementation of analytics module"},
+)
+```
+
+### HTTP Ingestion API (authorized write)
+
+`POST /api/v1/analytics/usage` is a **gated write**. It runs through
+`console_authz` action `record_analytics_usage` (operator+, Phase 2 execution).
+Unauthenticated or phase-inactive requests receive **403** and do not write.
+Prefer in-process `record_usage` for MCP / session instrumentation.
+
+```http
+POST /api/v1/analytics/usage HTTP/1.1
+Content-Type: application/json
+# Requires authenticated principal with record_analytics_usage execution enabled
+
+{
+  "remote": "dadeschools",
+  "org": "Scaled-Tech-Consulting",
+  "repo": "Gitea-Tools",
+  "role": "author",
+  "model": "gemini-3.6-flash",
+  "issue_number": 651,
+  "stage": "implementation",
+  "input_tokens": 1420,
+  "output_tokens": 380,
+  "total_tokens": 1800,
+  "estimated_cost_usd": 0.00045,
+  "latency_ms": 320,
+  "duration_ms": 4500,
+  "status": "success",
+  "metadata": "Analytics schema landed"
+}
+```
+
+### Retention
+
+`usage_events` is retained with hard caps applied on every write:
+
+| Limit | Default |
+|---|---|
+| Max rows | 10,000 (`ControlPlaneDB.USAGE_EVENTS_MAX_ROWS`) |
+| Max age | 90 days (`ControlPlaneDB.USAGE_EVENTS_RETENTION_DAYS`) |
+
+Older rows (by `created_at`) and excess oldest rows (by `usage_id`) are deleted
+after each insert so unbounded growth / DoS-by-volume cannot fill the DB.
+
+---
+
+## 6. Querying Analytics API
+
+```http
+GET /api/v1/analytics?role=author&stage=implementation HTTP/1.1
+```
+
+Returns `AnalyticsSnapshot` JSON containing aggregations (`by_model`, `by_stage`, `by_role`, `by_work_item`, `by_project`) and latency percentiles (`p50`, `p90`, `p95`, `p99`).

docs/webui-authz-audit.md

@@ -91,6 +91,7 @@ already define, and a regression test asserts each mapping matches.
 | `close_pr` | controller | privileged | `gitea.pr.close` | Yes | No | No | 3 |
 | `merge_pr` | controller | privileged | `gitea.pr.merge` | Yes | **Yes** | **Yes** | 3 |
 | `delete_branch` | admin | destructive | `gitea.branch.delete` | Yes | **Yes** | **Yes** | 3 |
+| `record_analytics_usage` | operator | gated_write | `runtime.record_analytics_usage` | Yes | No | No | 2 |
 | `system.reload_namespace` | controller | privileged | `runtime.reload_namespace` | Yes | No | No | 2 |
 | `system.restart_namespace` | admin | destructive | `runtime.restart_namespace` | Yes | **Yes** | **Yes** | 2 |
 

gitea_mcp_server.py

@@ -2065,6 +2065,7 @@ import allocator_dependencies  # noqa: E402
 import dependency_graph  # noqa: E402  # #784 durable dependency edges
 import control_plane_db  # noqa: E402
 import lease_lifecycle  # noqa: E402
+import lease_policy  # noqa: E402
 import workflow_dashboard  # noqa: E402  # #605 live queue/lease dashboard
 import restart_coordinator  # noqa: E402  # #658 MCP restart coordinator/impact
 import incident_bridge  # noqa: E402
@@ -2310,7 +2311,6 @@ import canonical_comment_validator as ccv  # noqa: E402
 # GITEA_ISSUE_LOCK_DIR, bound to the current MCP session via a per-PID pointer.
 # Legacy global path retained only for test/doc references — do not seed manually.
 ISSUE_LOCK_FILE = "/tmp/gitea_issue_lock.json"
-WORK_LEASE_TTL_HOURS = 4
 AUTHOR_ISSUE_WORK_LEASE = "author_issue_work"
 VALID_WORK_LEASE_OPERATIONS = frozenset({
     AUTHOR_ISSUE_WORK_LEASE,
@@ -2625,7 +2625,12 @@ def _build_author_issue_work_lease(
     host: str | None,
 ) -> dict:
     created = _work_lease_now()
-    expires = created + timedelta(hours=WORK_LEASE_TTL_HOURS)
+    # #790 Slice A: the window comes from the central policy, not a literal here.
+    # It is also now a *sliding* window — the lease lives ``initial_ttl_minutes``
+    # past its last valid heartbeat rather than a fixed four hours past its
+    # creation, so an abandoned task stops holding the claim within one TTL.
+    policy = lease_policy.policy_for(lease_policy.TASK_CLASS_AUTHOR_ISSUE_WORK)
+    expires = created + timedelta(minutes=policy.initial_ttl_minutes)
     return {
         "operation_type": AUTHOR_ISSUE_WORK_LEASE,
         "issue_number": issue_number,
@@ -2636,6 +2641,15 @@ def _build_author_issue_work_lease(
         "created_at": _work_lease_timestamp(created),
         "expires_at": _work_lease_timestamp(expires),
         "last_heartbeat_at": _work_lease_timestamp(created),
+        # #790 AC-N1: the ownership key for this task. Distinct from the recorded
+        # PID, which is the shared daemon and identifies no individual task.
+        "task_session_id": issue_lock_store.mint_task_session_id(
+            AUTHOR_ISSUE_WORK_LEASE
+        ),
+        # #790 AC-N8: the explicit lifecycle marker. Its absence — never a
+        # timestamp comparison — is what makes a lock legacy.
+        "lifecycle_version": lease_policy.LIFECYCLE_HEARTBEAT_V1,
+        "heartbeat_count": 1,
     }
 
 
@@ -4406,6 +4420,135 @@ def gitea_lock_issue(
 
 
 @mcp.tool()
+def gitea_heartbeat_issue_lock(
+    issue_number: int,
+    branch_name: str,
+    task_session_id: str | None = None,
+    remote: str = "dadeschools",
+    host: str | None = None,
+    org: str | None = None,
+    repo: str | None = None,
+    worktree_path: str | None = None,
+    expected_generation: int | None = None,
+) -> dict:
+    """Prove an owned author issue lease is still active (#790 Slice A).
+
+    The task-liveness signal the lifecycle was missing. Before this, an author
+    lease carried a fixed four-hour expiry that nothing could shorten, and the
+    only liveness evidence was the recorded PID — the long-lived MCP daemon,
+    which stays alive across every task it serves and so proved nothing about
+    whether the authoring task still held the work.
+
+    Each successful call slides the lease ``initial_ttl_minutes`` past *now*
+    from the central policy, so an actively heartbeating session is never
+    evicted while an abandoned one releases its claim within one TTL.
+
+    What this tool cannot do, by construction:
+
+    * **Acquire.** It refuses when no durable lock exists.
+    * **Take over.** Exact issue, branch, realpath-normalized worktree,
+      claimant username, claimant profile, and recorded task-session identifier
+      must all match; a superseded session holding an older identifier is
+      refused.
+    * **Revive.** A lease already past its grace is not heartbeatable — that
+      would let a session restore ownership it had stopped proving. It must use
+      the sanctioned reclaim path, which mints a new generation.
+
+    A lock predating the heartbeat lifecycle is rebound rather than heartbeated:
+    its exact owner is re-verified and a genuine task-session identifier and
+    first heartbeat are minted (#790 AC-N8). The rebind is decided server-side
+    from the durable lifecycle marker; there is no caller-facing switch.
+
+    Args:
+        issue_number: The locked issue number.
+        branch_name: The branch recorded on the lock.
+        task_session_id: The identifier this session received when it acquired
+            or rebound the lock. It is a fencing token, not an ownership
+            assertion: it is compared against durable state and can only ever
+            cause a refusal, never grant anything. Omitted only when rebinding a
+            legacy lock, which has no identifier yet and mints one.
+        remote: Known instance — 'dadeschools' or 'prgs'.
+        host: Override the Gitea host.
+        org: Override the owner/organization.
+        repo: Override the repository name.
+        worktree_path: Author worktree recorded on the lock.
+        expected_generation: Optional fencing value. The per-issue flock already
+            serializes the read and the write, so this is for a caller that
+            wants to pin the generation it last observed across calls; a moved
+            generation fails closed.
+
+    Returns:
+        dict with 'success', 'performed', the sliding 'expires_at',
+        'last_heartbeat_at', 'lock_generation', 'task_session_id', the applied
+        'policy', and post-write 'freshness'; on refusal 'success'/'performed'
+        False with 'reasons' naming exactly what did not match.
+    """
+    blocked = _profile_permission_block(
+        task_capability_map.required_permission("heartbeat_issue_lock"),
+        issue_number=issue_number,
+        remote=remote,
+        host=host,
+        org=org,
+        repo=repo,
+        org_explicit=org is not None,
+        repo_explicit=repo is not None,
+    )
+    if blocked:
+        return blocked
+
+    resolved_worktree = issue_lock_worktree.resolve_author_worktree_path(
+        worktree_path, _canonical_local_git_root()
+    )
+    h, o, r = _resolve(remote, host, org, repo)
+    claimant = _work_lease_claimant(h)
+    identity = claimant.get("username")
+    profile = claimant.get("profile")
+
+    existing = _load_existing_issue_lock(
+        remote=remote, org=o, repo=r, issue_number=issue_number
+    )
+    if not existing:
+        return {
+            "success": False,
+            "performed": False,
+            "issue_number": issue_number,
+            "reasons": [
+                f"no durable lock for issue #{issue_number}; heartbeat cannot "
+                "acquire a claim (fail closed)"
+            ],
+        }
+
+    if issue_lock_store.is_legacy_lease(existing):
+        outcome = issue_lock_store.rebind_legacy_lock(
+            remote=remote,
+            org=o,
+            repo=r,
+            issue_number=issue_number,
+            branch_name=branch_name,
+            worktree_path=resolved_worktree,
+            identity=identity,
+            profile=profile,
+            expected_generation=expected_generation,
+        )
+        outcome["operation"] = "legacy_rebind"
+        return outcome
+
+    outcome = issue_lock_store.heartbeat_session_lock(
+        remote=remote,
+        org=o,
+        repo=r,
+        issue_number=issue_number,
+        branch_name=branch_name,
+        worktree_path=resolved_worktree,
+        identity=identity,
+        profile=profile,
+        task_session_id=str(task_session_id or ""),
+        expected_generation=expected_generation,
+    )
+    outcome["operation"] = "heartbeat"
+    return outcome
+
+
 @mcp.tool()
 def gitea_recover_dirty_orphaned_issue_worktree(
     issue_number: int,
@@ -4679,6 +4822,7 @@ def gitea_recover_dirty_orphaned_issue_worktree(
         )
     return result
 
+
 @mcp.tool()
 def gitea_rebind_dirty_same_claimant_author_session(
     issue_number: int,
@@ -4935,8 +5079,6 @@ def gitea_rebind_dirty_same_claimant_author_session(
     }
     return result
 
-    return result
-
 
 @mcp.tool()
 def gitea_assess_work_issue_duplicate(

issue_lock_store.py

@@ -15,15 +15,27 @@ import json
 import os
 import re
 import tempfile
+import uuid
 from contextlib import contextmanager
 from datetime import datetime, timedelta, timezone
 from typing import Any
 
+import lease_policy
+
 LOCK_DIR_ENV = "GITEA_ISSUE_LOCK_DIR"
 DEFAULT_LOCK_DIR = os.path.expanduser("~/.cache/gitea-tools/issue-locks")
-WORK_LEASE_TTL_HOURS = 4
 AUTHOR_ISSUE_WORK_LEASE = "author_issue_work"
 
+# Freshness classifications. ``STATUS_STALE`` remains the dead-PID band that
+# #753 recovery keys on; the two bands below are new in #790 Slice A and apply
+# only to leases minted under the heartbeat lifecycle.
+STATUS_LIVE = "live"
+STATUS_EXPIRED = "expired"
+STATUS_ABSENT = "absent"
+STATUS_STALE = "stale"
+STATUS_STALE_MISSED_HEARTBEAT = "stale_missed_heartbeat"
+STATUS_STALE_ABSOLUTE_CAP = "stale_absolute_cap"
+
 _SAFE_SEGMENT_RE = re.compile(r"[^A-Za-z0-9._+-]+")
 
 
@@ -257,6 +269,331 @@ def bind_session_lock(
     return path
 
 
+def _ownership_refusals(
+    lock: dict[str, Any],
+    *,
+    issue_number: int,
+    branch_name: str,
+    worktree_path: str,
+    identity: str | None,
+    profile: str | None,
+) -> list[str]:
+    """Exact-ownership mismatches between a durable lock and a live caller.
+
+    Shared by the heartbeat writer and the legacy rebind path so the two cannot
+    disagree about what "the same owner" means. Every field is compared against
+    durable state; nothing is taken on the caller's word beyond the identity the
+    server itself resolved.
+    """
+    reasons: list[str] = []
+    if lock.get("issue_number") != issue_number:
+        reasons.append(
+            f"lock targets issue #{lock.get('issue_number')}, not #{issue_number}"
+        )
+    if str(lock.get("branch_name") or "") != str(branch_name or ""):
+        reasons.append(
+            f"lock branch '{lock.get('branch_name')}' does not match '{branch_name}'"
+        )
+    if not _same_realpath(str(lock.get("worktree_path") or ""), worktree_path):
+        reasons.append(
+            f"lock worktree '{lock.get('worktree_path')}' does not match "
+            f"'{worktree_path}'"
+        )
+    lease = lock.get("work_lease") if isinstance(lock, dict) else None
+    claimant = lease.get("claimant") if isinstance(lease, dict) else None
+    claimant = claimant if isinstance(claimant, dict) else {}
+    recorded_identity = str(claimant.get("username") or "").strip()
+    recorded_profile = str(claimant.get("profile") or "").strip()
+    if not recorded_identity or not recorded_profile:
+        reasons.append("lock does not record both a claimant username and profile")
+    if recorded_identity and recorded_identity != str(identity or "").strip():
+        reasons.append(
+            f"lock claimant '{recorded_identity}' does not match active identity "
+            f"'{str(identity or '').strip() or 'unknown'}'"
+        )
+    if recorded_profile and recorded_profile != str(profile or "").strip():
+        reasons.append(
+            f"lock profile '{recorded_profile}' does not match active profile "
+            f"'{str(profile or '').strip() or 'unknown'}'"
+        )
+    return reasons
+
+
+def _refusal(reasons: list[str], **extra: Any) -> dict[str, Any]:
+    return {"success": False, "performed": False, "reasons": reasons, **extra}
+
+
+def heartbeat_session_lock(
+    *,
+    remote: str,
+    org: str,
+    repo: str,
+    issue_number: int,
+    branch_name: str,
+    worktree_path: str,
+    identity: str | None,
+    profile: str | None,
+    task_session_id: str,
+    expected_generation: int | None = None,
+    lock_dir: str | None = None,
+    now: datetime | None = None,
+) -> dict[str, Any]:
+    """Slide a heartbeat-lifecycle lease forward (#790 Slice A, A4).
+
+    The write happens inside the same per-issue ``flock`` that serializes
+    acquisition, and under the #772 generation compare-and-swap, so a heartbeat
+    can never race a concurrent reclaim: whichever lands first moves the
+    generation and the other fails closed.
+
+    Refuses — never revives — in every ambiguous case. A lease that has already
+    lapsed past its grace is *not* heartbeatable: allowing that would let a
+    session that stopped proving liveness restore ownership retroactively, which
+    is precisely the revival AC-N5 forbids. Such a session must go through the
+    sanctioned reclaim path, which mints a fresh generation.
+    """
+    current = _lease_now(now)
+    root = _ensure_lock_dir(lock_dir)
+    path = lock_file_path(
+        remote=remote, org=org, repo=repo, issue_number=issue_number, lock_dir=root
+    )
+    declared_session = str(task_session_id or "").strip()
+    if not declared_session:
+        return _refusal(["no task_session_id supplied (fail closed)"])
+
+    sentinel = flock_path(path)
+    try:
+        with _exclusive_file_lock(sentinel):
+            lock = read_lock_file(path)
+            if not lock:
+                return _refusal([f"no durable lock for issue #{issue_number}"])
+
+            if is_legacy_lease(lock):
+                return _refusal(
+                    [
+                        "lock predates the heartbeat lifecycle; it must be rebound "
+                        "by its exact owner before it can be heartbeated"
+                    ],
+                    lifecycle=lease_lifecycle_version(lock),
+                    legacy_lease=True,
+                )
+
+            reasons = _ownership_refusals(
+                lock,
+                issue_number=issue_number,
+                branch_name=branch_name,
+                worktree_path=worktree_path,
+                identity=identity,
+                profile=profile,
+            )
+            recorded_session = lease_task_session_id(lock)
+            if not recorded_session:
+                reasons.append(
+                    "lock declares the heartbeat lifecycle but records no "
+                    "task_session_id (fail closed)"
+                )
+            elif recorded_session != declared_session:
+                # A superseded session holding an old identifier cannot heartbeat
+                # over the session that replaced it.
+                reasons.append(
+                    "task_session_id does not match the session recorded on the lock"
+                )
+            if reasons:
+                return _refusal(reasons)
+
+            current_generation = lock_generation(lock)
+            if (
+                expected_generation is not None
+                and current_generation != expected_generation
+            ):
+                return _refusal(
+                    [
+                        f"lock generation changed: expected {expected_generation}, "
+                        f"found {current_generation}; another session reclaimed or "
+                        "replaced this claim (fail closed)"
+                    ],
+                    lock_generation=current_generation,
+                )
+
+            freshness = assess_lock_freshness(lock, now=current)
+            if not freshness.get("live"):
+                return _refusal(
+                    [
+                        f"lease is not live ({freshness.get('status')}): "
+                        f"{freshness.get('reason')}; a lapsed lease must be "
+                        "reclaimed, not heartbeated"
+                    ],
+                    freshness=freshness,
+                )
+
+            policy = lease_policy.policy_for(lease_task_class(lock))
+            expires = current + timedelta(minutes=policy.initial_ttl_minutes)
+            record = dict(lock)
+            lease = dict(record.get("work_lease") or {})
+            prior_heartbeat = lease.get("last_heartbeat_at")
+            lease["last_heartbeat_at"] = _format_lease_timestamp(current)
+            lease["expires_at"] = _format_lease_timestamp(expires)
+            try:
+                lease["heartbeat_count"] = int(lease.get("heartbeat_count") or 0) + 1
+            except (TypeError, ValueError):
+                lease["heartbeat_count"] = 1
+            record["work_lease"] = lease
+            record["lock_generation"] = current_generation + 1
+            save_lock_file(path, record)
+    except LockContentionError as exc:
+        return _refusal([f"issue #{issue_number} lock contention: {exc} (fail closed)"])
+
+    return {
+        "success": True,
+        "performed": True,
+        "issue_number": issue_number,
+        "branch_name": branch_name,
+        "worktree_path": worktree_path,
+        "task_session_id": declared_session,
+        "lock_generation": record["lock_generation"],
+        "prior_generation": current_generation,
+        "prior_heartbeat_at": prior_heartbeat,
+        "last_heartbeat_at": lease["last_heartbeat_at"],
+        "expires_at": lease["expires_at"],
+        "heartbeat_count": lease["heartbeat_count"],
+        "lock_file_path": path,
+        "policy": lease_policy.describe(lease_task_class(record)),
+        "freshness": assess_lock_freshness(record, now=current),
+    }
+
+
+def rebind_legacy_lock(
+    *,
+    remote: str,
+    org: str,
+    repo: str,
+    issue_number: int,
+    branch_name: str,
+    worktree_path: str,
+    identity: str | None,
+    profile: str | None,
+    expected_generation: int | None = None,
+    lock_dir: str | None = None,
+    now: datetime | None = None,
+) -> dict[str, Any]:
+    """Move a legacy lock into the heartbeat lifecycle (#790 AC-N8).
+
+    One of the two sanctioned exits from the preserved-expiry legacy state; the
+    other is terminal retirement, which is Slice B. Only the exact recorded
+    owner may rebind, and only while the legacy lock is still live under its
+    original absolute expiry — an already-expired legacy lease belongs to the
+    #760 renewal path or #601 reclaim, and this must not become a second, weaker
+    way to revive one.
+
+    The rebind mints a genuine task-session identifier and a genuine first
+    heartbeat. It does not fabricate history: the original creation and expiry
+    are preserved under ``legacy_origin`` for audit, and the new lifecycle's
+    absolute cap runs from the rebind, not from the legacy claim.
+    """
+    current = _lease_now(now)
+    root = _ensure_lock_dir(lock_dir)
+    path = lock_file_path(
+        remote=remote, org=org, repo=repo, issue_number=issue_number, lock_dir=root
+    )
+    sentinel = flock_path(path)
+    try:
+        with _exclusive_file_lock(sentinel):
+            lock = read_lock_file(path)
+            if not lock:
+                return _refusal([f"no durable lock for issue #{issue_number}"])
+            if not is_legacy_lease(lock):
+                return _refusal(
+                    [
+                        "lock is already on the heartbeat lifecycle; use the "
+                        "heartbeat path"
+                    ],
+                    lifecycle=lease_lifecycle_version(lock),
+                    legacy_lease=False,
+                )
+
+            reasons = _ownership_refusals(
+                lock,
+                issue_number=issue_number,
+                branch_name=branch_name,
+                worktree_path=worktree_path,
+                identity=identity,
+                profile=profile,
+            )
+            if reasons:
+                return _refusal(reasons)
+
+            current_generation = lock_generation(lock)
+            if (
+                expected_generation is not None
+                and current_generation != expected_generation
+            ):
+                return _refusal(
+                    [
+                        f"lock generation changed: expected {expected_generation}, "
+                        f"found {current_generation} (fail closed)"
+                    ],
+                    lock_generation=current_generation,
+                )
+
+            freshness = assess_lock_freshness(lock, now=current)
+            if not freshness.get("live"):
+                return _refusal(
+                    [
+                        f"legacy lease is not live ({freshness.get('status')}): "
+                        f"{freshness.get('reason')}; rebinding is not a recovery "
+                        "path for a lapsed lease"
+                    ],
+                    freshness=freshness,
+                )
+
+            policy = lease_policy.policy_for(lease_task_class(lock))
+            expires = current + timedelta(minutes=policy.initial_ttl_minutes)
+            session_id = mint_task_session_id(lease_task_class(lock))
+            record = dict(lock)
+            lease = dict(record.get("work_lease") or {})
+            legacy_origin = {
+                "created_at": lease.get("created_at"),
+                "expires_at": lease.get("expires_at"),
+                "last_heartbeat_at": lease.get("last_heartbeat_at"),
+                "lifecycle": lease_policy.LIFECYCLE_LEGACY,
+            }
+            lease["lifecycle_version"] = lease_policy.LIFECYCLE_HEARTBEAT_V1
+            lease["task_session_id"] = session_id
+            lease["created_at"] = _format_lease_timestamp(current)
+            lease["last_heartbeat_at"] = _format_lease_timestamp(current)
+            lease["expires_at"] = _format_lease_timestamp(expires)
+            lease["heartbeat_count"] = 1
+            record["work_lease"] = lease
+            record["legacy_rebind"] = {
+                "rebound_at": _format_lease_timestamp(current),
+                "task_session_id": session_id,
+                "prior_generation": current_generation,
+                "legacy_origin": legacy_origin,
+                "reason": (
+                    "legacy lock rebound into the heartbeat lifecycle by its exact "
+                    "recorded owner"
+                ),
+            }
+            record["lock_generation"] = current_generation + 1
+            save_lock_file(path, record)
+    except LockContentionError as exc:
+        return _refusal([f"issue #{issue_number} lock contention: {exc} (fail closed)"])
+
+    return {
+        "success": True,
+        "performed": True,
+        "issue_number": issue_number,
+        "task_session_id": session_id,
+        "lock_generation": record["lock_generation"],
+        "prior_generation": current_generation,
+        "lifecycle": lease_policy.LIFECYCLE_HEARTBEAT_V1,
+        "legacy_rebind": record["legacy_rebind"],
+        "expires_at": lease["expires_at"],
+        "last_heartbeat_at": lease["last_heartbeat_at"],
+        "lock_file_path": path,
+        "freshness": assess_lock_freshness(record, now=current),
+    }
+
+
 def read_session_issue_lock(lock_dir: str | None = None) -> dict[str, Any] | None:
     root = (lock_dir or default_lock_dir()).strip()
     pointer = read_lock_file(session_pointer_path(root))
@@ -340,6 +677,16 @@ def _parse_lease_timestamp(value: str | None) -> datetime | None:
         return None
 
 
+def _format_lease_timestamp(value: datetime) -> str:
+    """Serialize a lease timestamp in the durable ``...Z`` form already on disk."""
+    return (
+        value.astimezone(timezone.utc)
+        .replace(microsecond=0)
+        .isoformat()
+        .replace("+00:00", "Z")
+    )
+
+
 def lease_expires_at(lock: dict[str, Any] | None) -> datetime | None:
     if not lock:
         return None
@@ -360,26 +707,113 @@ def is_lease_live(lock: dict[str, Any] | None, *, now: datetime | None = None) -
     return assess_lock_freshness(lock, now=now)["live"]
 
 
+def lease_task_class(lock_data: dict[str, Any] | None) -> str:
+    """Policy task class for a durable lock; author work when unrecorded."""
+    lease = lock_data.get("work_lease") if isinstance(lock_data, dict) else None
+    if isinstance(lease, dict):
+        recorded = str(lease.get("operation_type") or "").strip()
+        if recorded:
+            return recorded
+    return AUTHOR_ISSUE_WORK_LEASE
+
+
+def lease_lifecycle_version(lock_data: dict[str, Any] | None) -> str:
+    """Read the durable lifecycle marker (#790 AC-N8).
+
+    The marker is the *only* discriminator between a heartbeat-lifecycle lease
+    and a legacy one. Timestamps are deliberately not consulted: a lock minted
+    before this lifecycle existed has ``last_heartbeat_at == created_at``
+    forever, and reading that equality as "recently heartbeated" would treat
+    every never-heartbeated legacy lock as fresh — the precise inversion AC-N8
+    forbids. A newly minted heartbeat lease also has the two equal, so the
+    equality carries no information in either direction.
+    """
+    lease = lock_data.get("work_lease") if isinstance(lock_data, dict) else None
+    if isinstance(lease, dict):
+        recorded = str(lease.get("lifecycle_version") or "").strip()
+        if recorded:
+            return recorded
+    return lease_policy.LIFECYCLE_LEGACY
+
+
+def is_legacy_lease(lock_data: dict[str, Any] | None) -> bool:
+    """True when a lock predates the shared heartbeat lifecycle."""
+    return lease_lifecycle_version(lock_data) != lease_policy.LIFECYCLE_HEARTBEAT_V1
+
+
+def lease_task_session_id(lock_data: dict[str, Any] | None) -> str:
+    """Recorded per-task session identifier, or empty for a legacy lock."""
+    lease = lock_data.get("work_lease") if isinstance(lock_data, dict) else None
+    if isinstance(lease, dict):
+        return str(lease.get("task_session_id") or "").strip()
+    return ""
+
+
+def mint_task_session_id(task_class: str = AUTHOR_ISSUE_WORK_LEASE) -> str:
+    """Mint an ownership key for one task (#790 AC-N1).
+
+    Deliberately contains no process identifier. The recorded PID belongs to the
+    long-lived MCP daemon, which outlives any individual task and is reused by
+    every task it serves, so PID digits cannot identify *which* task holds a
+    claim. The PID is still recorded alongside this value as evidence.
+    """
+    prefix = _sanitize_segment(str(task_class or AUTHOR_ISSUE_WORK_LEASE))
+    return f"{prefix}-{uuid.uuid4().hex[:16]}"
+
+
+def _lease_heartbeat_at(lock_data: dict[str, Any] | None) -> datetime | None:
+    lease = lock_data.get("work_lease") if isinstance(lock_data, dict) else None
+    heartbeat_at = None
+    if isinstance(lock_data, dict):
+        heartbeat_at = _parse_lease_timestamp(lock_data.get("last_heartbeat_at"))
+    if heartbeat_at is None and isinstance(lease, dict):
+        heartbeat_at = _parse_lease_timestamp(lease.get("last_heartbeat_at"))
+    return heartbeat_at
+
+
 def assess_lock_freshness(
     lock_data: dict[str, Any] | None,
     *,
     now: datetime | None = None,
 ) -> dict[str, Any]:
-    """Classify a lock as live, expired, stale, or absent."""
+    """Classify a lock as live, expired, stale, or absent.
+
+    #790 Slice A makes the heartbeat load-bearing. Before this change
+    ``last_heartbeat_at`` was parsed and then never consulted: liveness was
+    decided entirely by the absolute ``expires_at`` and by PID liveness, and
+    since the recorded PID is the long-lived MCP daemon, an abandoned author
+    task stayed "live" for the full four-hour TTL.
+
+    Two rules govern the rewrite:
+
+    * **An alive PID never establishes freshness** (AC-N2). It proves the daemon
+      is up, nothing about the task. It is recorded as evidence and no branch
+      returns ``live`` because of it.
+    * **A dead PID still corroborates staleness.** The dead-PID band is
+      unchanged and still precedes every heartbeat evaluation, so #753
+      dead-session recovery keys on exactly the classification it always did.
+
+    Legacy leases (AC-N8) keep their recorded absolute expiry and are never
+    evaluated against the short heartbeat grace, so deploying this change cannot
+    make an existing claim instantly reclaimable.
+    """
     current = _lease_now(now)
     if not lock_data:
         return {
-            "status": "absent",
+            "status": STATUS_ABSENT,
             "live": False,
             "stale": False,
             "reason": "no lock record",
         }
 
-    expires_at = lease_expires_at(lock_data)
     lease = lock_data.get("work_lease")
-    heartbeat_at = _parse_lease_timestamp(lock_data.get("last_heartbeat_at"))
+    expires_at = lease_expires_at(lock_data)
-    if heartbeat_at is None and isinstance(lease, dict):
+    heartbeat_at = _lease_heartbeat_at(lock_data)
-        heartbeat_at = _parse_lease_timestamp(lease.get("last_heartbeat_at"))
+    created_at = (
+        _parse_lease_timestamp(lease.get("created_at"))
+        if isinstance(lease, dict)
+        else None
+    )
 
     pid = lock_data.get("session_pid")
     if pid is None:
@@ -397,55 +831,102 @@ def assess_lock_freshness(
         pid_int = None
     pid_alive = is_process_alive(pid_int) if pid_int is not None else False
 
-    if expires_at and expires_at <= current:
+    lifecycle = lease_lifecycle_version(lock_data)
-        return {
+    legacy = lifecycle != lease_policy.LIFECYCLE_HEARTBEAT_V1
-            "status": "expired",
+    policy = lease_policy.policy_for(lease_task_class(lock_data))
-            "live": False,
+
-            "stale": True,
+    evidence: dict[str, Any] = {
-            "reason": f"lease expired at {expires_at.isoformat()}",
         "pid_alive": pid_alive,
         "pid_missing": pid_missing,
+        "lifecycle": lifecycle,
+        "legacy_lease": legacy,
+        "task_session_id": lease_task_session_id(lock_data) or None,
+        "heartbeat_at": heartbeat_at.isoformat() if heartbeat_at else None,
+        "expires_at": expires_at.isoformat() if expires_at else None,
     }
 
-    # #860: a PID-less lock must never be considered live merely because
+    def _result(status: str, *, live: bool, reason: str, **extra: Any) -> dict[str, Any]:
-    # expiration / heartbeat fields are absent. Missing PID is insufficient
-    # evidence of a live owner; treat as malformed/stale so recovery routes
-    # can evaluate corroborating pins instead of blocking on a false live flag.
-    if pid_missing:
         return {
-            "status": "malformed",
+            "status": status,
-            "live": False,
+            "live": live,
-            "stale": True,
+            "stale": not live and status != STATUS_ABSENT,
-            "reason": (
+            "reason": reason,
-                "lock has no usable session pid; cannot prove live ownership "
+            **evidence,
-                "(PID-less locks are never live by missing expiry alone)"
+            **extra,
+        }
+
+    if legacy:
+        # AC-N8: the preserved absolute expiry is the only clock for a lock
+        # written before task-session heartbeats existed.
+        if expires_at and expires_at <= current:
+            return _result(
+                STATUS_EXPIRED,
+                live=False,
+                reason=f"lease expired at {expires_at.isoformat()}",
+            )
+        if pid is not None and not pid_alive:
+            return _result(
+                STATUS_STALE, live=False, reason=f"owner pid {pid} is not alive"
+            )
+        return _result(
+            STATUS_LIVE,
+            live=True,
+            reason=(
+                "legacy lease is within its recorded absolute expiry; the "
+                "heartbeat grace does not apply retroactively"
             ),
-            "pid_alive": False,
+            legacy_expiry_preserved=True,
-            "pid_missing": True,
+        )
-            "heartbeat_at": heartbeat_at.isoformat() if heartbeat_at else None,
-            "expires_at": expires_at.isoformat() if expires_at else None,
-        }
 
-    if pid_int is not None and not pid_alive:
+    # ── Heartbeat lifecycle ──
-        return {
+    if pid is not None and not pid_alive:
-            "status": "stale",
+        # Unchanged dead-PID band: #753 recovery depends on this exact status.
-            "live": False,
+        return _result(STATUS_STALE, live=False, reason=f"owner pid {pid} is not alive")
-            "stale": True,
-            "reason": f"owner pid {pid_int} is not alive",
-            "pid_alive": False,
-            "pid_missing": False,
-        }
 
-    return {
+    if heartbeat_at is None:
-        "status": "live",
+        # Contradictory: a heartbeat lease must carry a heartbeat. Fail closed.
-        "live": True,
+        return _result(
-        "stale": False,
+            STATUS_STALE_MISSED_HEARTBEAT,
-        "reason": "lock heartbeat and lease are fresh",
+            live=False,
-        "pid_alive": pid_alive,
+            reason=(
-        "pid_missing": False,
+                f"lease declares lifecycle '{lifecycle}' but records no "
-        "heartbeat_at": heartbeat_at.isoformat() if heartbeat_at else None,
+                "last_heartbeat_at (fail closed)"
-        "expires_at": expires_at.isoformat() if expires_at else None,
+            ),
-    }
+        )
+
+    if policy.absolute_cap_hours and created_at is not None:
+        cap_at = created_at + timedelta(hours=policy.absolute_cap_hours)
+        if cap_at <= current:
+            return _result(
+                STATUS_STALE_ABSOLUTE_CAP,
+                live=False,
+                reason=(
+                    f"lease exceeded its {policy.absolute_cap_hours}h absolute cap "
+                    f"at {cap_at.isoformat()}; canonical re-adoption is required"
+                ),
+                absolute_cap_at=cap_at.isoformat(),
+            )
+
+    grace_at = heartbeat_at + timedelta(minutes=policy.missed_heartbeat_grace_minutes)
+    if grace_at <= current or (expires_at is not None and expires_at <= current):
+        return _result(
+            STATUS_STALE_MISSED_HEARTBEAT,
+            live=False,
+            reason=(
+                f"no valid heartbeat since {heartbeat_at.isoformat()}; the "
+                f"{policy.missed_heartbeat_grace_minutes}min grace lapsed at "
+                f"{grace_at.isoformat()}"
+            ),
+            missed_heartbeat_since=grace_at.isoformat(),
+        )
+
+    warning_at = heartbeat_at + timedelta(minutes=policy.stale_warning_minutes)
+    return _result(
+        STATUS_LIVE,
+        live=True,
+        reason="lease heartbeat is fresh within the configured grace",
+        heartbeat_warning=warning_at <= current,
+    )
 
 
 def _same_realpath(left: str | None, right: str | None) -> bool:
@@ -483,6 +964,27 @@ def assess_expired_lock_reclaim(
             "reasons": ["lock is still live; cannot reclaim (fail closed)"],
             "freshness": freshness,
         }
+    status = str(freshness.get("status") or "")
+    if status in (STATUS_STALE_MISSED_HEARTBEAT, STATUS_STALE_ABSOLUTE_CAP):
+        # #790: under the heartbeat lifecycle the heartbeat *is* the liveness
+        # proof, so a session that stopped heartbeating past its grace has
+        # released its claim by definition. Requiring a dead PID on top of that
+        # would reinstate the original defect — the recorded PID is the shared
+        # daemon, which stays alive across every abandoned task it ever served.
+        #
+        # This band is unreachable for a legacy lease (AC-N8), so no lock
+        # written before this lifecycle can be reclaimed by this path.
+        return {
+            "reclaim_allowed": True,
+            "reasons": [
+                f"heartbeat-lifecycle lease is {status}: {freshness.get('reason')}"
+            ],
+            "freshness": freshness,
+            "prior_branch": existing_lock.get("branch_name"),
+            "prior_worktree": existing_lock.get("worktree_path"),
+            "prior_pid": existing_lock.get("session_pid") or existing_lock.get("pid"),
+            "prior_task_session_id": lease_task_session_id(existing_lock) or None,
+        }
     pid = existing_lock.get("session_pid")
     if pid is None:
         pid = existing_lock.get("pid")
@@ -557,7 +1059,28 @@ def assess_same_issue_lease_conflict(
     )
     if recovery_sanctioned and existing_issue == issue_number and existing_branch == branch_name:
         return None
-    if is_lease_expired(existing_lock, now=now):
+    expired = is_lease_expired(existing_lock, now=now)
+    # #790 review #502/#516: a heartbeat-lifecycle lease that is non-live but
+    # whose absolute expires_at is still in the future must enter the same
+    # reclaim/renewal disposition as an expired lease. This happens for
+    # stale_absolute_cap (a session that keeps heartbeating past the 8h cap has
+    # expires_at = last_heartbeat + TTL in the future) and for
+    # stale_missed_heartbeat under an independent TTL>grace policy. Keying this
+    # gate on is_lease_expired alone left assess_expired_lock_reclaim — which
+    # already permits exactly those bands — unreachable from the acquisition
+    # path, so the load-bearing heartbeat was not load-bearing for foreign
+    # reclaim: the precise abandonment scenario #790 exists to fix.
+    # assess_foreign_lock_overwrite already keys on is_lease_live; this makes the
+    # same-issue path consistent with it. Legacy leases keep their absolute-expiry
+    # clock (AC-N8): is_lease_live already decides a legacy lease from expires_at
+    # / dead-PID alone and is_legacy_lease excludes it here, so this widening is a
+    # no-op for every pre-lifecycle lock.
+    heartbeat_non_live_reclaimable = (
+        not expired
+        and not is_legacy_lease(existing_lock)
+        and not is_lease_live(existing_lock, now=now)
+    )
+    if expired or heartbeat_non_live_reclaimable:
         # #760 AC1/AC2: exact-owner renewal is a different disposition from
         # foreign takeover and is evaluated first. Before this, both branches
         # below returned unconditionally, so the same_owner allowance further
@@ -571,10 +1094,12 @@ def assess_same_issue_lease_conflict(
         reclaim = assess_expired_lock_reclaim(existing_lock, now=now)
         if reclaim.get("reclaim_allowed"):
             # #601: expired + dead pid / missing worktree may be reclaimed
-            # through the normal lock path (sanctioned overwrite).
+            # through the normal lock path (sanctioned overwrite). #790: the new
+            # stale heartbeat bands are reclaimable here on the same evidence.
             return None
+        descriptor = "expired" if expired else "non-live"
         return (
-            f"Issue #{issue_number} has an expired {operation_type} lease on "
+            f"Issue #{issue_number} has an {descriptor} {operation_type} lease on "
             f"branch '{existing_branch}' from worktree '{existing_worktree}'. "
             "Recovery review is required before takeover (fail closed)"
         )

lease_policy.py

@@ -0,0 +1,212 @@
+"""Central lease policy configuration (#790 Slice A, AC-N7).
+
+The single authoritative source for every lease duration in the project. Before
+this module the numbers were scattered: a four-hour author TTL was declared
+twice (``issue_lock_store`` and ``gitea_mcp_server``), the reviewer/merger
+sliding window lived in ``reviewer_pr_lease``, the conflict-fix window in
+``pr_work_lease``, and the control-plane default in ``control_plane_db``.
+Nothing tied them together, so tuning one class silently diverged from the
+others and no reader could answer "how long does a lease live?" without
+grepping four files.
+
+AC-N7 requires that this configuration exist *before* the first heartbeat and
+TTL behavior that reads from it, so it ships in Slice A rather than trailing the
+code it governs.
+
+Deliberate boundaries:
+
+* **Declaration is not rewiring.** Every task class is declared here, but only
+  those with ``heartbeat_lifecycle_active`` were migrated onto the shared
+  heartbeat lifecycle in Slice A — currently ``author_issue_work`` alone.
+  Reviewer, merger, and conflict-fix leases keep their own existing behavior
+  until Slice C moves them; their numbers are recorded here so the two cannot
+  drift apart unnoticed, and ``tests/test_issue_790_lease_policy.py`` asserts
+  the recorded values still equal the constants those modules use.
+* **No policy decision lives here.** This module answers "how long", never "may
+  this session proceed". Freshness, reclaim, and renewal dispositions stay in
+  ``issue_lock_store``.
+"""
+
+from __future__ import annotations
+
+import os
+from dataclasses import dataclass
+from typing import Any
+
+# Task classes. Only the first is migrated onto the shared lifecycle in Slice A.
+TASK_CLASS_AUTHOR_ISSUE_WORK = "author_issue_work"
+TASK_CLASS_REVIEWER_PR = "reviewer_pr"
+TASK_CLASS_MERGER_PR = "merger_pr"
+TASK_CLASS_CONFLICT_FIX = "conflict_fix"
+
+# Durable marker for a lease minted under the shared heartbeat lifecycle.
+#
+# #790 AC-N8: this explicit marker — never a timestamp comparison — is what
+# distinguishes a heartbeat-lifecycle lease from a legacy one. A lock written
+# before this lifecycle existed carries no marker and reads as
+# ``LIFECYCLE_LEGACY``.
+LIFECYCLE_HEARTBEAT_V1 = "heartbeat-v1"
+LIFECYCLE_LEGACY = "legacy"
+
+_ENV_PREFIX = "GITEA_LEASE_POLICY"
+
+
+@dataclass(frozen=True)
+class LeasePolicy:
+    """Durations governing one task class.
+
+    All intervals are minutes except ``absolute_cap_hours``. ``None`` for the
+    cap means the class has no maximum continuous duration.
+    """
+
+    task_class: str
+    initial_ttl_minutes: float
+    heartbeat_cadence_minutes: float
+    stale_warning_minutes: float
+    missed_heartbeat_grace_minutes: float
+    absolute_cap_hours: float | None
+    recovery_grace_minutes: float
+    terminal_race_drain_minutes: float
+    terminal_retirement_eligible: bool
+    heartbeat_lifecycle_active: bool
+
+
+# Defaults. ``author_issue_work`` adopts the reviewer window proven by #747
+# rather than inventing new numbers: a lease expires 10 minutes after its last
+# valid heartbeat, warns at half that, and an actively heartbeating session is
+# never evicted. The prior value was a fixed four hours (240 minutes) that no
+# heartbeat could shorten — the defect this issue exists to correct.
+_DEFAULTS: dict[str, LeasePolicy] = {
+    TASK_CLASS_AUTHOR_ISSUE_WORK: LeasePolicy(
+        task_class=TASK_CLASS_AUTHOR_ISSUE_WORK,
+        initial_ttl_minutes=10.0,
+        heartbeat_cadence_minutes=2.0,
+        stale_warning_minutes=5.0,
+        missed_heartbeat_grace_minutes=10.0,
+        absolute_cap_hours=8.0,
+        recovery_grace_minutes=10.0,
+        terminal_race_drain_minutes=2.0,
+        terminal_retirement_eligible=True,
+        heartbeat_lifecycle_active=True,
+    ),
+    # Declared, not rewired. These mirror reviewer_pr_lease.LEASE_TTL_MINUTES
+    # and STALE_WARNING_MINUTES; Slice C migrates the call sites.
+    TASK_CLASS_REVIEWER_PR: LeasePolicy(
+        task_class=TASK_CLASS_REVIEWER_PR,
+        initial_ttl_minutes=10.0,
+        heartbeat_cadence_minutes=2.0,
+        stale_warning_minutes=5.0,
+        missed_heartbeat_grace_minutes=10.0,
+        absolute_cap_hours=None,
+        recovery_grace_minutes=10.0,
+        terminal_race_drain_minutes=2.0,
+        terminal_retirement_eligible=False,
+        heartbeat_lifecycle_active=False,
+    ),
+    TASK_CLASS_MERGER_PR: LeasePolicy(
+        task_class=TASK_CLASS_MERGER_PR,
+        initial_ttl_minutes=10.0,
+        heartbeat_cadence_minutes=2.0,
+        stale_warning_minutes=5.0,
+        missed_heartbeat_grace_minutes=10.0,
+        absolute_cap_hours=None,
+        recovery_grace_minutes=10.0,
+        terminal_race_drain_minutes=2.0,
+        terminal_retirement_eligible=False,
+        heartbeat_lifecycle_active=False,
+    ),
+    # Mirrors pr_work_lease.DEFAULT_CONFLICT_FIX_TTL_MINUTES. Deliberately left
+    # at its current window; shortening it is Slice C's call, not this slice's.
+    TASK_CLASS_CONFLICT_FIX: LeasePolicy(
+        task_class=TASK_CLASS_CONFLICT_FIX,
+        initial_ttl_minutes=120.0,
+        heartbeat_cadence_minutes=2.0,
+        stale_warning_minutes=5.0,
+        missed_heartbeat_grace_minutes=10.0,
+        absolute_cap_hours=None,
+        recovery_grace_minutes=10.0,
+        terminal_race_drain_minutes=2.0,
+        terminal_retirement_eligible=False,
+        heartbeat_lifecycle_active=False,
+    ),
+}
+
+_NUMERIC_FIELDS = (
+    "initial_ttl_minutes",
+    "heartbeat_cadence_minutes",
+    "stale_warning_minutes",
+    "missed_heartbeat_grace_minutes",
+    "absolute_cap_hours",
+    "recovery_grace_minutes",
+    "terminal_race_drain_minutes",
+)
+
+
+def env_var_name(task_class: str, field: str) -> str:
+    """Environment variable that overrides one field of one task class."""
+    return f"{_ENV_PREFIX}_{task_class.upper()}_{field.upper()}"
+
+
+def _override(task_class: str, field: str, default: float | None) -> float | None:
+    """Read one override, falling back to *default* on anything unusable.
+
+    A malformed or non-positive override is ignored rather than raised: a typo
+    in an environment variable must not be able to mint a zero-length lease that
+    makes every claim instantly reclaimable, nor crash the server at import.
+    """
+    raw = (os.environ.get(env_var_name(task_class, field)) or "").strip()
+    if not raw:
+        return default
+    try:
+        value = float(raw)
+    except (TypeError, ValueError):
+        return default
+    if value <= 0:
+        return default
+    return value
+
+
+def policy_for(task_class: str) -> LeasePolicy:
+    """Return the effective policy for *task_class*.
+
+    Unknown task classes fall back to the author policy, which is the most
+    conservative migrated class, rather than raising — a new caller must never
+    be able to crash a lock write by naming a class this table has not learned.
+    """
+    key = str(task_class or "").strip() or TASK_CLASS_AUTHOR_ISSUE_WORK
+    base = _DEFAULTS.get(key) or _DEFAULTS[TASK_CLASS_AUTHOR_ISSUE_WORK]
+    resolved = {
+        field: _override(base.task_class, field, getattr(base, field))
+        for field in _NUMERIC_FIELDS
+    }
+    if all(resolved[field] == getattr(base, field) for field in _NUMERIC_FIELDS):
+        return base
+    return LeasePolicy(
+        task_class=base.task_class,
+        terminal_retirement_eligible=base.terminal_retirement_eligible,
+        heartbeat_lifecycle_active=base.heartbeat_lifecycle_active,
+        **resolved,
+    )
+
+
+def known_task_classes() -> tuple[str, ...]:
+    """Every declared task class, migrated or not."""
+    return tuple(_DEFAULTS)
+
+
+def describe(task_class: str) -> dict[str, Any]:
+    """Serializable view of a policy, for audit records and tool payloads."""
+    policy = policy_for(task_class)
+    return {
+        "task_class": policy.task_class,
+        "initial_ttl_minutes": policy.initial_ttl_minutes,
+        "heartbeat_cadence_minutes": policy.heartbeat_cadence_minutes,
+        "stale_warning_minutes": policy.stale_warning_minutes,
+        "missed_heartbeat_grace_minutes": policy.missed_heartbeat_grace_minutes,
+        "absolute_cap_hours": policy.absolute_cap_hours,
+        "recovery_grace_minutes": policy.recovery_grace_minutes,
+        "terminal_race_drain_minutes": policy.terminal_race_drain_minutes,
+        "terminal_retirement_eligible": policy.terminal_retirement_eligible,
+        "heartbeat_lifecycle_active": policy.heartbeat_lifecycle_active,
+        "lifecycle_version": LIFECYCLE_HEARTBEAT_V1,
+    }

task_capability_map.py

@@ -32,6 +32,15 @@ TASK_CAPABILITY_MAP: dict[str, dict[str, str]] = {
         "permission": "gitea.issue.comment",
         "role": "author",
     },
+    # #790 Slice A: prove an owned author lease is still active. Strictly
+    # narrower than lock_issue — it can only slide a lease this exact session
+    # already owns, never acquire, take over, or revive one — so it gates on the
+    # same authority rather than introducing an operation name that every
+    # already-configured author profile would be missing.
+    "heartbeat_issue_lock": {
+        "permission": "gitea.issue.comment",
+        "role": "author",
+    },
     # #860: dirty orphaned same-claimant worktree recovery (explicit operation).
     "recover_dirty_orphaned_issue_worktree": {
         "permission": "gitea.issue.comment",
@@ -510,6 +519,15 @@ TASK_CAPABILITY_MAP: dict[str, dict[str, str]] = {
         "permission": "gitea.issue.comment",
         "role": "author",
     },
+
+    # #651 console analytics ingest — control-plane DB write, not a Gitea API
+    # call. Authority comes from console RBAC (operator+) plus phase gating;
+    # permission string is a non-Gitea runtime capability so no Gitea profile
+    # can satisfy it by accident.
+    "record_analytics_usage": {
+        "permission": "runtime.record_analytics_usage",
+        "role": "author",
+    },
 }
 
 

tests/test_control_plane_db.py

@@ -36,7 +36,7 @@ class ControlPlaneDBTest(unittest.TestCase):
             rows = dict(conn.execute("SELECT key, value FROM schema_meta").fetchall())
         finally:
             conn.close()
-        self.assertEqual(rows["schema_version"], "4")
+        self.assertEqual(rows["schema_version"], "5")
         self.assertIn("DB coordinates", rows["architecture"])
         self.assertIn("bridge", rows["architecture"].lower())
 

tests/test_issue_628_orchestration.py

@@ -0,0 +1,199 @@
+"""Regression tests for #628 building blocks (child scope only).
+
+Honest scope: unit coverage of pre-existing APIs used by umbrella #628.
+This module does **not** implement or verify all 21 umbrella acceptance
+criteria, automatic handoff store/retrieve, multi-worker product wiring,
+or end-to-end orchestration.
+
+Covered building blocks:
+- CTH format / parse / assess (`format_cth_body`, `parse_cth_comment`,
+  `assess_cth_comment`)
+- Exclusive-ownership skip classification (`classify_skip` with
+  OWNERSHIP_FOREIGN vs OWNERSHIP_OWN)
+- Durable dependency edges (`upsert_dependency_edge` / list) and skip
+  when dependency_unmet
+- Edge state transition UNMET -> MET
+
+Parent umbrella remains #628; this slice is a scoped child issue only.
+"""
+
+import unittest
+from unittest.mock import MagicMock, patch
+import os
+import json
+import tempfile
+
+from canonical_thread_handoff import (
+    format_cth_body,
+    parse_cth_comment,
+    assess_cth_comment,
+)
+import dependency_graph
+from control_plane_db import ControlPlaneDB
+from allocator_service import (
+    WorkCandidate,
+    classify_skip,
+    ROLE_AUTHOR,
+    ROLE_REVIEWER,
+    ROLE_MERGER,
+    ROLE_RECONCILER,
+    OWNERSHIP_OWN,
+    OWNERSHIP_FOREIGN,
+)
+
+
+class TestIssue628Orchestration(unittest.TestCase):
+    def setUp(self):
+        self._tmp = tempfile.TemporaryDirectory()
+        self.db_path = os.path.join(self._tmp.name, "cp.sqlite3")
+        self.db = ControlPlaneDB(self.db_path)
+
+    def tearDown(self):
+        self._tmp.cleanup()
+
+    def test_canonical_handoff_serialization_and_retrieval(self):
+        """Building block: format/parse/assess a CTH body (not full AC1/AC2 product path)."""
+        handoff = format_cth_body(
+            cth_type="Author Handoff",
+            status="completed",
+            next_owner="reviewer",
+            current_blocker="none",
+            decision="Implementation complete, tests passing",
+            proof="pytest tests/test_issue_628_orchestration.py passed",
+            next_action="Review PR and run reviewer pre-flight",
+            ready_to_paste_prompt="Review PR for child issue #878 (parent #628)",
+        )
+        self.assertIn("CTH: Author Handoff", handoff)
+
+        parsed = parse_cth_comment(handoff)
+        self.assertIsNotNone(parsed)
+        self.assertEqual(parsed["cth_type"], "Author Handoff")
+
+        assessment = assess_cth_comment(handoff)
+        self.assertFalse(assessment["block"])
+
+    def test_exclusive_task_unit_single_owner(self):
+        """Building block: classify_skip foreign vs own ownership."""
+        candidate = WorkCandidate(
+            kind="issue",
+            number=878,
+            title="Child #878 ownership classify candidate",
+            state="open",
+            labels=["status:in-progress"],
+            blocked=False,
+            dependency_unmet=False,
+        )
+        # Foreign ownership MUST be skipped
+        skip_foreign = classify_skip(
+            c=candidate,
+            role=ROLE_AUTHOR,
+            terminal_pr=None,
+            claim_ownership=OWNERSHIP_FOREIGN,
+        )
+        self.assertIsNotNone(skip_foreign)
+        self.assertIn("active lease", skip_foreign)
+
+        # Own/Self claim remains selectable for session resumption
+        skip_self = classify_skip(
+            c=candidate,
+            role=ROLE_AUTHOR,
+            terminal_pr=None,
+            claim_ownership=OWNERSHIP_OWN,
+        )
+        self.assertIsNone(skip_self)
+
+    def test_durable_dependency_graph_blocking(self):
+        """Building block: unmet dependency edge + classify_skip on dependency_unmet."""
+        # Upsert a blocking dependency edge between issue 878 and blocker 601
+        self.db.upsert_dependency_edge(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            source_kind="issue",
+            source_number=878,
+            target_kind="issue",
+            target_number=601,
+            edge_type=dependency_graph.EDGE_ISSUE_BLOCKED_BY_ISSUE,
+            state=dependency_graph.STATE_UNMET,
+            blocking_condition="Target issue #601 is not closed",
+            completion_condition="Target issue #601 is closed",
+            evidence={"source": "unit_test"},
+        )
+
+        edges = self.db.list_dependency_edges(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            source_kind="issue",
+            source_number=878,
+        )
+        self.assertEqual(len(edges), 1)
+        self.assertEqual(edges[0]["state"], "unmet")
+        self.assertEqual(edges[0]["target_number"], 601)
+
+        # When dependency is unmet, candidate is blocked from selection
+        candidate = WorkCandidate(
+            kind="issue",
+            number=878,
+            title="Blocked candidate",
+            state="open",
+            labels=[],
+            blocked=False,
+            dependency_unmet=True,
+            dependency_reason="issue#878 is blocked by unmet dependency issue#601",
+        )
+        skip_reason = classify_skip(
+            c=candidate,
+            role=ROLE_AUTHOR,
+            terminal_pr=None,
+            claim_ownership=OWNERSHIP_OWN,
+        )
+        self.assertIsNotNone(skip_reason)
+        self.assertIn("issue#601", skip_reason)
+
+    def test_dependency_completion_reevaluation(self):
+        """Building block: dependency edge state can transition UNMET -> MET."""
+        self.db.upsert_dependency_edge(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            source_kind="issue",
+            source_number=878,
+            target_kind="issue",
+            target_number=601,
+            edge_type=dependency_graph.EDGE_ISSUE_BLOCKED_BY_ISSUE,
+            state=dependency_graph.STATE_UNMET,
+            blocking_condition="Target issue #601 is open",
+            completion_condition="Target issue #601 is closed",
+            evidence={"source": "unit_test"},
+        )
+
+        # Mark edge as met upon target issue closure
+        self.db.upsert_dependency_edge(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            source_kind="issue",
+            source_number=878,
+            target_kind="issue",
+            target_number=601,
+            edge_type=dependency_graph.EDGE_ISSUE_BLOCKED_BY_ISSUE,
+            state=dependency_graph.STATE_MET,
+            blocking_condition="Target issue #601 is open",
+            completion_condition="Target issue #601 is closed",
+            evidence={"source": "target_closed_event"},
+        )
+
+        edges = self.db.list_dependency_edges(
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            source_kind="issue",
+            source_number=878,
+        )
+        self.assertEqual(len(edges), 1)
+        self.assertEqual(edges[0]["state"], "met")
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_issue_790_heartbeat_mcp_path.py

@@ -0,0 +1,444 @@
+"""Task heartbeat through the native MCP author path (#790 Slice A, AC-N6).
+
+Assessor-level coverage is not sufficient here, and this project has already
+paid for learning that: in review #499 on PR #791 the #760 renewal waiver was
+computed correctly and then *discarded* at two later gates, so every real
+renewal still failed while the unit suite stayed green. AC-N6 exists because of
+that, and requires driving the real tools against a real git repository and a
+real durable lock file, composing the gates in production order.
+
+These tests therefore call ``gitea_lock_issue`` and
+``gitea_heartbeat_issue_lock`` themselves and assert on what lands on disk,
+never on an assessor's return value alone.
+"""
+
+from __future__ import annotations
+
+import os
+import subprocess
+import sys
+import tempfile
+import unittest
+from datetime import datetime, timedelta, timezone
+from unittest.mock import patch
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
+
+from mutation_profile_fixture import shared_mutation_env  # noqa: E402
+
+import issue_lock_provenance  # noqa: E402
+import issue_lock_store  # noqa: E402
+import lease_policy  # noqa: E402
+import mcp_server  # noqa: E402
+
+ISSUE = 9791
+BRANCH = f"fix/issue-{ISSUE}-heartbeat-mcp"
+IDENTITY = "example-user"
+PROFILE = "test-author-prgs"
+ORG = "Scaled-Tech-Consulting"
+REPO = "Gitea-Tools"
+
+
+def _ts(moment: datetime) -> str:
+    return (
+        moment.astimezone(timezone.utc)
+        .replace(microsecond=0)
+        .isoformat()
+        .replace("+00:00", "Z")
+    )
+
+
+class _HeartbeatMcpBase(unittest.TestCase):
+    """Real git repo plus a real durable lock, driven through the real tools."""
+
+    def setUp(self):
+        self.lock_dir = tempfile.TemporaryDirectory()
+        self.addCleanup(self.lock_dir.cleanup)
+        self.repo = tempfile.mkdtemp(prefix="issue790-mcp-")
+        self.addCleanup(lambda: subprocess.run(["rm", "-rf", self.repo], check=False))
+        self._init_worktree()
+        self.remotes = patch.dict(
+            mcp_server.REMOTES,
+            {"prgs": {"host": "gitea.prgs.cc", "org": ORG, "repo": REPO}},
+        )
+        self.remotes.start()
+        self.addCleanup(patch.stopall)
+        mcp_server._IDENTITY_CACHE.clear()
+
+    def _git(self, *args):
+        return subprocess.run(
+            ["git", "-C", self.repo, *args], capture_output=True, text=True, check=True
+        )
+
+    def _init_worktree(self):
+        self._git("init", "-q", "-b", "master")
+        self._git("config", "user.email", "[email protected]")
+        self._git("config", "user.name", "Test")
+        with open(os.path.join(self.repo, "seed.txt"), "w") as fh:
+            fh.write("seed\n")
+        self._git("add", "seed.txt")
+        self._git("commit", "-q", "-m", "seed")
+        self.base_sha = self._git("rev-parse", "HEAD").stdout.strip()
+        # A fresh claim starts base-equivalent, which is the ordinary first-lock
+        # shape and exercises assess_issue_lock_worktree on its normal path.
+        self._git("checkout", "-q", "-b", BRANCH)
+        self.head_sha = self.base_sha
+        self.worktree = os.path.realpath(self.repo)
+
+    def _lock_path(self):
+        return issue_lock_store.lock_file_path(
+            remote="prgs",
+            org=ORG,
+            repo=REPO,
+            issue_number=ISSUE,
+            lock_dir=self.lock_dir.name,
+        )
+
+    def _tool_env(self):
+        env = shared_mutation_env(
+            PROFILE, include_example_repo=True, GITEA_ISSUE_LOCK_DIR=self.lock_dir.name
+        )
+        env["GITEA_ISSUE_LOCK_DIR"] = self.lock_dir.name
+        return env
+
+    def _git_state(self, *, porcelain="", base_equivalent=True):
+        return {
+            "current_branch": BRANCH,
+            "porcelain_status": porcelain,
+            "base_equivalent": base_equivalent,
+            "head_sha": self.head_sha,
+            "inspected_git_root": self.worktree,
+            "base_branch": "master",
+        }
+
+    def run_lock_issue(
+        self,
+        *,
+        branch_entries=None,
+        open_prs=None,
+        git_state=None,
+        identity=IDENTITY,
+        profile=PROFILE,
+    ):
+        branch_entries = branch_entries if branch_entries is not None else []
+        open_prs = open_prs if open_prs is not None else []
+        git_state = git_state or self._git_state()
+        env = self._tool_env()
+        with patch(
+            "mcp_server.api_get_all", return_value=list(branch_entries)
+        ), patch(
+            "mcp_server._list_open_pulls", return_value=list(open_prs)
+        ), patch(
+            "mcp_server.get_auth_header", return_value="token x"
+        ), patch(
+            "mcp_server._work_lease_claimant",
+            return_value={"username": identity, "profile": profile},
+        ), patch(
+            "mcp_server.issue_lock_worktree.read_worktree_git_state",
+            return_value=git_state,
+        ), patch(
+            "mcp_server.issue_duplicate_context_fetcher",
+            side_effect=lambda h, o, r, auth, issue_number: (
+                list(open_prs),
+                [b.get("name") for b in branch_entries if isinstance(b, dict)],
+                {"status": "not_claimed"},
+            ),
+        ), patch.dict(os.environ, env, clear=True):
+            os.environ["GITEA_ISSUE_LOCK_DIR"] = self.lock_dir.name
+            return mcp_server.gitea_lock_issue(
+                issue_number=ISSUE,
+                branch_name=BRANCH,
+                remote="prgs",
+                worktree_path=self.worktree,
+            )
+
+    def run_heartbeat(
+        self, *, task_session_id, identity=IDENTITY, profile=PROFILE, **kwargs
+    ):
+        env = self._tool_env()
+        with patch(
+            "mcp_server._work_lease_claimant",
+            return_value={"username": identity, "profile": profile},
+        ), patch("mcp_server.get_auth_header", return_value="token x"), patch.dict(
+            os.environ, env, clear=True
+        ):
+            os.environ["GITEA_ISSUE_LOCK_DIR"] = self.lock_dir.name
+            return mcp_server.gitea_heartbeat_issue_lock(
+                issue_number=ISSUE,
+                branch_name=kwargs.pop("branch_name", BRANCH),
+                task_session_id=task_session_id,
+                remote="prgs",
+                worktree_path=kwargs.pop("worktree_path", self.worktree),
+                **kwargs,
+            )
+
+    def write_legacy_lock(self, *, hours_old: float = 3.0, ttl_hours: float = 4.0):
+        """A durable lock in the shape the store wrote before this slice."""
+        now = datetime.now(timezone.utc)
+        claimant = {"username": IDENTITY, "profile": PROFILE}
+        created = now - timedelta(hours=hours_old)
+        record = {
+            "issue_number": ISSUE,
+            "branch_name": BRANCH,
+            "remote": "prgs",
+            "org": ORG,
+            "repo": REPO,
+            "worktree_path": self.worktree,
+            "session_pid": os.getpid(),
+            "pid": os.getpid(),
+            "lock_generation": 1,
+            "work_lease": {
+                "operation_type": issue_lock_store.AUTHOR_ISSUE_WORK_LEASE,
+                "issue_number": ISSUE,
+                "pr_number": None,
+                "branch": BRANCH,
+                "worktree_path": self.worktree,
+                "claimant": claimant,
+                "created_at": _ts(created),
+                # The legacy signature: never advanced past creation.
+                "last_heartbeat_at": _ts(created),
+                "expires_at": _ts(created + timedelta(hours=ttl_hours)),
+            },
+            "lock_provenance": issue_lock_provenance.build_sanctioned_lock_provenance(
+                tool="gitea_lock_issue", claimant=claimant
+            ),
+        }
+        path = self._lock_path()
+        record["lock_file_path"] = path
+        issue_lock_store.save_lock_file(path, record)
+        return record
+
+
+class TestLockIssueMintsTheLifecycle(_HeartbeatMcpBase):
+    """Durable lock creation and read-back through the real tool."""
+
+    def test_native_lock_writes_the_marker_and_a_task_session_id(self):
+        result = self.run_lock_issue()
+        self.assertTrue(result["success"], result)
+
+        written = issue_lock_store.read_lock_file(result["lock_file_path"])
+        lease = written["work_lease"]
+        self.assertEqual(
+            lease["lifecycle_version"], lease_policy.LIFECYCLE_HEARTBEAT_V1
+        )
+        self.assertTrue(lease["task_session_id"])
+        self.assertFalse(issue_lock_store.is_legacy_lease(written))
+        # AC-N1: the ownership key is not the daemon pid, which is recorded
+        # separately as evidence.
+        self.assertNotIn(str(written["session_pid"]), lease["task_session_id"])
+        self.assertEqual(written["session_pid"], os.getpid())
+
+    def test_native_lease_uses_the_policy_window_not_four_hours(self):
+        result = self.run_lock_issue()
+        lease = result["work_lease"]
+        created = datetime.fromisoformat(lease["created_at"].replace("Z", "+00:00"))
+        expires = datetime.fromisoformat(lease["expires_at"].replace("Z", "+00:00"))
+        policy = lease_policy.policy_for(lease_policy.TASK_CLASS_AUTHOR_ISSUE_WORK)
+        self.assertEqual(
+            (expires - created).total_seconds() / 60.0, policy.initial_ttl_minutes
+        )
+
+    def test_freshness_of_a_new_native_lock_is_live(self):
+        result = self.run_lock_issue()
+        self.assertEqual(
+            result["lock_freshness"]["status"], issue_lock_store.STATUS_LIVE
+        )
+        self.assertTrue(result["lock_freshness"]["live"])
+
+
+class TestHeartbeatThroughTheTool(_HeartbeatMcpBase):
+    def _lock_and_session(self):
+        result = self.run_lock_issue()
+        self.assertTrue(result["success"], result)
+        return result, result["work_lease"]["task_session_id"]
+
+    def test_heartbeat_slides_the_lease_and_advances_the_generation(self):
+        locked, session = self._lock_and_session()
+        before = issue_lock_store.read_lock_file(locked["lock_file_path"])
+
+        beat = self.run_heartbeat(task_session_id=session)
+
+        self.assertTrue(beat["success"], beat)
+        self.assertEqual(beat["operation"], "heartbeat")
+        after = issue_lock_store.read_lock_file(locked["lock_file_path"])
+        self.assertGreater(
+            issue_lock_store.lock_generation(after),
+            issue_lock_store.lock_generation(before),
+        )
+        self.assertGreaterEqual(
+            after["work_lease"]["expires_at"], before["work_lease"]["expires_at"]
+        )
+        self.assertEqual(after["work_lease"]["heartbeat_count"], 2)
+
+    def test_heartbeat_evidence_survives_the_downstream_mutation_gate(self):
+        """The #499 F2 lesson, applied.
+
+        A sanction that is computed and then discarded downstream is worthless.
+        After a heartbeat the lock must still satisfy the gate every author
+        mutation runs through.
+        """
+        locked, session = self._lock_and_session()
+        self.run_heartbeat(task_session_id=session)
+
+        written = issue_lock_store.read_lock_file(locked["lock_file_path"])
+        verdict = issue_lock_store.verify_lock_for_mutation(
+            written,
+            issue_number=ISSUE,
+            branch_name=BRANCH,
+            worktree_path=self.worktree,
+        )
+        self.assertTrue(verdict["proven"], verdict)
+        self.assertFalse(verdict["block"])
+
+    def _duplicate_gate(self, *, open_prs, branches):
+        env = self._tool_env()
+        with patch("mcp_server.get_auth_header", return_value="token x"), patch(
+            "mcp_server.issue_duplicate_context_fetcher",
+            side_effect=lambda h, o, r, auth, issue_number: (
+                list(open_prs),
+                list(branches),
+                {"status": "not_claimed"},
+            ),
+        ), patch.dict(os.environ, env, clear=True):
+            os.environ["GITEA_ISSUE_LOCK_DIR"] = self.lock_dir.name
+            return mcp_server.gitea_assess_work_issue_duplicate(
+                issue_number=ISSUE, branch_name=BRANCH, remote="prgs"
+            )
+
+    def test_heartbeat_does_not_change_the_duplicate_gate_verdict(self):
+        """The gate must be invariant under heartbeating.
+
+        The point is not that the gate passes — with a linked open PR at the
+        lock phase it correctly blocks (#400), heartbeat or not. The property
+        that matters is that sliding a lease neither loosens the gate nor
+        corrupts the lock state it reads: the verdict before and after a
+        heartbeat must be identical, for both the clear and the blocking shape.
+        """
+        _, session = self._lock_and_session()
+        linked = [{"number": 4242, "head": {"ref": BRANCH, "sha": self.head_sha}}]
+
+        clear_before = self._duplicate_gate(open_prs=[], branches=[])
+        blocked_before = self._duplicate_gate(open_prs=linked, branches=[BRANCH])
+
+        self.assertTrue(self.run_heartbeat(task_session_id=session)["success"])
+
+        clear_after = self._duplicate_gate(open_prs=[], branches=[])
+        blocked_after = self._duplicate_gate(open_prs=linked, branches=[BRANCH])
+
+        self.assertEqual(clear_before["outcome"], clear_after["outcome"])
+        self.assertFalse(clear_after["block"])
+        self.assertEqual(blocked_before["outcome"], blocked_after["outcome"])
+        self.assertTrue(blocked_after["block"])
+        self.assertEqual(blocked_after["linked_open_pr"], 4242)
+
+    def test_foreign_session_id_is_refused_through_the_tool(self):
+        self._lock_and_session()
+        beat = self.run_heartbeat(task_session_id="author_issue_work-ffffffffffffffff")
+        self.assertFalse(beat["success"])
+        self.assertIn("task_session_id does not match", " ".join(beat["reasons"]))
+
+    def test_stale_generation_is_refused_through_the_tool(self):
+        locked, session = self._lock_and_session()
+        current = issue_lock_store.lock_generation(
+            issue_lock_store.read_lock_file(locked["lock_file_path"])
+        )
+        beat = self.run_heartbeat(
+            task_session_id=session, expected_generation=current + 5
+        )
+        self.assertFalse(beat["success"])
+        self.assertIn("generation changed", beat["reasons"][0])
+
+    def test_foreign_claimant_is_refused_through_the_tool(self):
+        _, session = self._lock_and_session()
+        beat = self.run_heartbeat(task_session_id=session, identity="someone-else")
+        self.assertFalse(beat["success"])
+
+    def test_heartbeat_cannot_acquire_a_missing_lock(self):
+        beat = self.run_heartbeat(task_session_id="author_issue_work-000000000000")
+        self.assertFalse(beat["success"])
+        self.assertIn("no durable lock", beat["reasons"][0])
+
+    def test_alive_pid_alone_does_not_keep_a_lease_live_through_the_tool(self):
+        """PID-only refusal, end to end.
+
+        The recorded pid is this live process. The lock is aged past its grace
+        with no heartbeat, so the tool must refuse to slide it and the durable
+        record must classify as a missed heartbeat rather than as live.
+        """
+        locked, session = self._lock_and_session()
+        record = issue_lock_store.read_lock_file(locked["lock_file_path"])
+        record["work_lease"]["last_heartbeat_at"] = _ts(
+            datetime.now(timezone.utc) - timedelta(minutes=30)
+        )
+        record["work_lease"]["expires_at"] = _ts(
+            datetime.now(timezone.utc) + timedelta(hours=2)
+        )
+        issue_lock_store.save_lock_file(locked["lock_file_path"], record)
+
+        self.assertTrue(issue_lock_store.is_process_alive(record["session_pid"]))
+        fresh = issue_lock_store.assess_lock_freshness(record)
+        self.assertEqual(
+            fresh["status"], issue_lock_store.STATUS_STALE_MISSED_HEARTBEAT
+        )
+        self.assertTrue(fresh["pid_alive"])
+
+        beat = self.run_heartbeat(task_session_id=session)
+        self.assertFalse(beat["success"])
+        self.assertIn("reclaimed", " ".join(beat["reasons"]))
+
+
+class TestLegacyLocksThroughTheTool(_HeartbeatMcpBase):
+    """AC-N8 end to end: protected on deployment, and rebindable."""
+
+    def test_legacy_lock_stays_protected_after_deployment(self):
+        record = self.write_legacy_lock(hours_old=3.0, ttl_hours=4.0)
+        fresh = issue_lock_store.assess_lock_freshness(record)
+        self.assertEqual(fresh["status"], issue_lock_store.STATUS_LIVE)
+        self.assertTrue(fresh["legacy_lease"])
+        self.assertTrue(fresh["legacy_expiry_preserved"])
+        # It had never heartbeated, so under the new grace alone it would be
+        # long gone; the preserved absolute expiry is what protects it.
+        self.assertEqual(
+            record["work_lease"]["created_at"],
+            record["work_lease"]["last_heartbeat_at"],
+        )
+
+    def test_tool_rebinds_a_legacy_lock_and_mints_a_first_heartbeat(self):
+        self.write_legacy_lock(hours_old=3.0, ttl_hours=4.0)
+
+        result = self.run_heartbeat(task_session_id=None)
+
+        self.assertTrue(result["success"], result)
+        self.assertEqual(result["operation"], "legacy_rebind")
+        self.assertTrue(result["task_session_id"])
+
+        written = issue_lock_store.read_lock_file(self._lock_path())
+        lease = written["work_lease"]
+        self.assertEqual(
+            lease["lifecycle_version"], lease_policy.LIFECYCLE_HEARTBEAT_V1
+        )
+        self.assertEqual(lease["heartbeat_count"], 1)
+        self.assertNotEqual(
+            lease["created_at"],
+            written["legacy_rebind"]["legacy_origin"]["created_at"],
+        )
+        self.assertFalse(issue_lock_store.is_legacy_lease(written))
+
+    def test_rebound_lock_then_heartbeats_through_the_tool(self):
+        self.write_legacy_lock(hours_old=3.0, ttl_hours=4.0)
+        rebound = self.run_heartbeat(task_session_id=None)
+        beat = self.run_heartbeat(task_session_id=rebound["task_session_id"])
+        self.assertTrue(beat["success"], beat)
+        self.assertEqual(beat["operation"], "heartbeat")
+        self.assertEqual(beat["heartbeat_count"], 2)
+
+    def test_rebind_refuses_a_foreign_owner_through_the_tool(self):
+        self.write_legacy_lock(hours_old=3.0, ttl_hours=4.0)
+        result = self.run_heartbeat(task_session_id=None, identity="someone-else")
+        self.assertFalse(result["success"])
+        self.assertEqual(result["operation"], "legacy_rebind")
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_issue_790_lease_policy.py

@@ -0,0 +1,594 @@
+"""Central lease policy and load-bearing heartbeat freshness (#790 Slice A).
+
+Before this slice, ``issue_lock_store.assess_lock_freshness`` parsed
+``last_heartbeat_at`` and then never consulted it: liveness was decided by an
+absolute four-hour ``expires_at`` and by PID liveness. Because the recorded PID
+is the long-lived MCP daemon rather than the authoring task, an abandoned claim
+stayed "live" for the full four hours, and a claim whose work had already landed
+blocked reconciliation for just as long (Issue #787 / PR #789, and again Issue
+#760 / PR #791).
+
+These tests pin the corrected semantics, including the two asymmetries that are
+easy to lose in a refactor:
+
+* an **alive** PID must never make anything live (AC-N2), while
+* a **dead** PID must still mark a lease stale, because #753 dead-session
+  recovery keys on exactly that classification.
+
+Durable-state helpers here write real lock files through the real flock path;
+they are not mocks of the store.
+"""
+
+from __future__ import annotations
+
+import os
+import sys
+import tempfile
+import unittest
+from datetime import datetime, timedelta, timezone
+from unittest.mock import patch
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+import issue_lock_store  # noqa: E402
+import lease_policy  # noqa: E402
+import pr_work_lease  # noqa: E402
+import reviewer_pr_lease  # noqa: E402
+
+ISSUE = 9790
+BRANCH = f"fix/issue-{ISSUE}-heartbeat"
+IDENTITY = "example-user"
+PROFILE = "test-author-prgs"
+ORG = "Example-Org"
+REPO = "Example-Repo"
+REMOTE = "prgs"
+DEAD_PID = 2**22  # far above any live pid on a test host
+
+
+def _ts(moment: datetime) -> str:
+    return (
+        moment.astimezone(timezone.utc)
+        .replace(microsecond=0)
+        .isoformat()
+        .replace("+00:00", "Z")
+    )
+
+
+class _LockFixture(unittest.TestCase):
+    def setUp(self):
+        self.lock_dir = tempfile.TemporaryDirectory()
+        self.addCleanup(self.lock_dir.cleanup)
+        self.now = datetime.now(timezone.utc)
+        self.worktree = os.path.realpath(tempfile.mkdtemp(prefix="issue790-"))
+        self.addCleanup(patch.stopall)
+
+    def _path(self):
+        return issue_lock_store.lock_file_path(
+            remote=REMOTE,
+            org=ORG,
+            repo=REPO,
+            issue_number=ISSUE,
+            lock_dir=self.lock_dir.name,
+        )
+
+    def write_lock(
+        self,
+        *,
+        lifecycle: str | None = lease_policy.LIFECYCLE_HEARTBEAT_V1,
+        created_delta: timedelta = timedelta(minutes=1),
+        heartbeat_delta: timedelta = timedelta(minutes=1),
+        expires_delta: timedelta = timedelta(minutes=9),
+        pid: int | None = None,
+        task_session_id: str | None = "author_issue_work-aaaabbbbccccdddd",
+        generation: int = 1,
+        identity: str = IDENTITY,
+        profile: str = PROFILE,
+        branch: str = BRANCH,
+        worktree: str | None = None,
+    ) -> dict:
+        """Write a real durable lock and return the record.
+
+        Deltas are relative to ``self.now``; ``expires_delta`` is added, the
+        others subtracted, so "in the past" reads naturally at each call site.
+        """
+        lease: dict = {
+            "operation_type": issue_lock_store.AUTHOR_ISSUE_WORK_LEASE,
+            "issue_number": ISSUE,
+            "pr_number": None,
+            "branch": branch,
+            "worktree_path": worktree or self.worktree,
+            "claimant": {"username": identity, "profile": profile},
+            "created_at": _ts(self.now - created_delta),
+            "last_heartbeat_at": _ts(self.now - heartbeat_delta),
+            "expires_at": _ts(self.now + expires_delta),
+        }
+        if lifecycle is not None:
+            lease["lifecycle_version"] = lifecycle
+            if task_session_id is not None:
+                lease["task_session_id"] = task_session_id
+        pid_value = os.getpid() if pid is None else pid
+        record = {
+            "issue_number": ISSUE,
+            "branch_name": branch,
+            "remote": REMOTE,
+            "org": ORG,
+            "repo": REPO,
+            "worktree_path": worktree or self.worktree,
+            "session_pid": pid_value,
+            "pid": pid_value,
+            "lock_generation": generation,
+            "work_lease": lease,
+        }
+        path = self._path()
+        record["lock_file_path"] = path
+        issue_lock_store.save_lock_file(path, record)
+        return record
+
+
+class TestPolicyIsTheSingleSource(unittest.TestCase):
+    """AC-N7: one authoritative configuration source for every duration."""
+
+    def test_author_policy_carries_the_agreed_values(self):
+        policy = lease_policy.policy_for(lease_policy.TASK_CLASS_AUTHOR_ISSUE_WORK)
+        self.assertEqual(policy.initial_ttl_minutes, 10.0)
+        self.assertEqual(policy.heartbeat_cadence_minutes, 2.0)
+        self.assertEqual(policy.stale_warning_minutes, 5.0)
+        self.assertEqual(policy.missed_heartbeat_grace_minutes, 10.0)
+        self.assertEqual(policy.absolute_cap_hours, 8.0)
+        self.assertEqual(policy.recovery_grace_minutes, 10.0)
+        self.assertEqual(policy.terminal_race_drain_minutes, 2.0)
+        self.assertTrue(policy.terminal_retirement_eligible)
+        self.assertTrue(policy.heartbeat_lifecycle_active)
+
+    def test_the_four_hour_author_ttl_literal_is_gone(self):
+        """The duplicated literal AC-N7 exists to remove."""
+        self.assertFalse(hasattr(issue_lock_store, "WORK_LEASE_TTL_HOURS"))
+        import gitea_mcp_server
+
+        self.assertFalse(hasattr(gitea_mcp_server, "WORK_LEASE_TTL_HOURS"))
+
+    def test_declared_reviewer_values_match_the_module_still_using_them(self):
+        """Slice A declares reviewer/merger numbers without rewiring them.
+
+        Recording a value in two places is only safe if drift is detectable, so
+        this asserts the declaration still equals the constants #747 owns. When
+        Slice C migrates those call sites, this test becomes the proof the
+        migration changed nothing.
+        """
+        policy = lease_policy.policy_for(lease_policy.TASK_CLASS_REVIEWER_PR)
+        self.assertEqual(
+            policy.initial_ttl_minutes, float(reviewer_pr_lease.LEASE_TTL_MINUTES)
+        )
+        self.assertEqual(
+            policy.stale_warning_minutes,
+            float(reviewer_pr_lease.STALE_WARNING_MINUTES),
+        )
+        self.assertFalse(policy.heartbeat_lifecycle_active)
+
+    def test_declared_conflict_fix_value_matches_its_module(self):
+        policy = lease_policy.policy_for(lease_policy.TASK_CLASS_CONFLICT_FIX)
+        self.assertEqual(
+            policy.initial_ttl_minutes,
+            float(pr_work_lease.DEFAULT_CONFLICT_FIX_TTL_MINUTES),
+        )
+        self.assertFalse(policy.heartbeat_lifecycle_active)
+
+    def test_environment_override_applies(self):
+        var = lease_policy.env_var_name(
+            lease_policy.TASK_CLASS_AUTHOR_ISSUE_WORK, "initial_ttl_minutes"
+        )
+        with patch.dict(os.environ, {var: "7"}):
+            self.assertEqual(
+                lease_policy.policy_for(
+                    lease_policy.TASK_CLASS_AUTHOR_ISSUE_WORK
+                ).initial_ttl_minutes,
+                7.0,
+            )
+
+    def test_unusable_override_falls_back_instead_of_minting_a_zero_lease(self):
+        """A typo must not make every claim instantly reclaimable."""
+        var = lease_policy.env_var_name(
+            lease_policy.TASK_CLASS_AUTHOR_ISSUE_WORK, "initial_ttl_minutes"
+        )
+        for bad in ("0", "-5", "not-a-number", "   "):
+            with self.subTest(value=bad), patch.dict(os.environ, {var: bad}):
+                self.assertEqual(
+                    lease_policy.policy_for(
+                        lease_policy.TASK_CLASS_AUTHOR_ISSUE_WORK
+                    ).initial_ttl_minutes,
+                    10.0,
+                )
+
+    def test_unknown_task_class_does_not_raise(self):
+        policy = lease_policy.policy_for("something-new")
+        self.assertEqual(policy.task_class, lease_policy.TASK_CLASS_AUTHOR_ISSUE_WORK)
+
+
+class TestLifecycleDiscrimination(_LockFixture):
+    """AC-N8: the marker, never a timestamp, decides legacy vs heartbeat."""
+
+    def test_missing_marker_reads_as_legacy(self):
+        record = self.write_lock(lifecycle=None)
+        self.assertTrue(issue_lock_store.is_legacy_lease(record))
+        self.assertEqual(
+            issue_lock_store.lease_lifecycle_version(record),
+            lease_policy.LIFECYCLE_LEGACY,
+        )
+
+    def test_marker_present_reads_as_heartbeat_lifecycle(self):
+        record = self.write_lock()
+        self.assertFalse(issue_lock_store.is_legacy_lease(record))
+
+    def test_equal_created_and_heartbeat_never_implies_a_fresh_heartbeat(self):
+        """The exact inversion AC-N8 forbids.
+
+        A legacy lock has ``last_heartbeat_at == created_at`` forever because
+        nothing ever advanced it. Reading that equality as "recently
+        heartbeated" would classify every never-heartbeated lock as fresh.
+        """
+        legacy = self.write_lock(
+            lifecycle=None,
+            created_delta=timedelta(hours=3),
+            heartbeat_delta=timedelta(hours=3),
+        )
+        lease = legacy["work_lease"]
+        self.assertEqual(lease["created_at"], lease["last_heartbeat_at"])
+        self.assertTrue(issue_lock_store.is_legacy_lease(legacy))
+
+        # A brand-new heartbeat lease has them equal too, so the equality
+        # carries no information in either direction.
+        fresh = self.write_lock(
+            created_delta=timedelta(seconds=0), heartbeat_delta=timedelta(seconds=0)
+        )
+        self.assertEqual(
+            fresh["work_lease"]["created_at"],
+            fresh["work_lease"]["last_heartbeat_at"],
+        )
+        self.assertFalse(issue_lock_store.is_legacy_lease(fresh))
+
+    def test_minted_session_id_contains_no_pid(self):
+        """AC-N1: the ownership key must not be derived from the daemon pid."""
+        minted = issue_lock_store.mint_task_session_id()
+        self.assertNotIn(str(os.getpid()), minted)
+        self.assertNotEqual(minted, issue_lock_store.mint_task_session_id())
+
+
+class TestFreshnessIsHeartbeatDriven(_LockFixture):
+    """AC-N2 and the new bands."""
+
+    def test_fresh_heartbeat_is_live(self):
+        record = self.write_lock(heartbeat_delta=timedelta(minutes=1))
+        fresh = issue_lock_store.assess_lock_freshness(record, now=self.now)
+        self.assertEqual(fresh["status"], issue_lock_store.STATUS_LIVE)
+        self.assertTrue(fresh["live"])
+        self.assertFalse(fresh["heartbeat_warning"])
+
+    def test_heartbeat_past_warning_is_still_live_but_flagged(self):
+        record = self.write_lock(heartbeat_delta=timedelta(minutes=6))
+        fresh = issue_lock_store.assess_lock_freshness(record, now=self.now)
+        self.assertEqual(fresh["status"], issue_lock_store.STATUS_LIVE)
+        self.assertTrue(fresh["heartbeat_warning"])
+
+    def test_missed_heartbeat_past_grace_is_classified_explicitly(self):
+        record = self.write_lock(
+            heartbeat_delta=timedelta(minutes=11),
+            expires_delta=timedelta(minutes=30),
+        )
+        fresh = issue_lock_store.assess_lock_freshness(record, now=self.now)
+        self.assertEqual(
+            fresh["status"], issue_lock_store.STATUS_STALE_MISSED_HEARTBEAT
+        )
+        self.assertFalse(fresh["live"])
+        self.assertTrue(fresh["stale"])
+
+    def test_alive_pid_never_establishes_freshness(self):
+        """The defect in one assertion.
+
+        The recorded PID is this very process, so it is unambiguously alive —
+        and the lease is still not live, because the task stopped heartbeating.
+        """
+        record = self.write_lock(
+            pid=os.getpid(),
+            heartbeat_delta=timedelta(hours=4),
+            expires_delta=timedelta(hours=4),
+        )
+        fresh = issue_lock_store.assess_lock_freshness(record, now=self.now)
+        self.assertTrue(fresh["pid_alive"])
+        self.assertFalse(fresh["live"])
+        self.assertEqual(
+            fresh["status"], issue_lock_store.STATUS_STALE_MISSED_HEARTBEAT
+        )
+
+    def test_dead_pid_still_marks_stale_for_issue_753(self):
+        """The opposite asymmetry: dead-PID corroboration is preserved."""
+        record = self.write_lock(pid=DEAD_PID, heartbeat_delta=timedelta(minutes=1))
+        fresh = issue_lock_store.assess_lock_freshness(record, now=self.now)
+        self.assertEqual(fresh["status"], issue_lock_store.STATUS_STALE)
+        self.assertFalse(fresh["live"])
+        self.assertIn("not alive", fresh["reason"])
+
+    def test_absolute_cap_requires_readoption(self):
+        record = self.write_lock(
+            created_delta=timedelta(hours=9), heartbeat_delta=timedelta(minutes=1)
+        )
+        fresh = issue_lock_store.assess_lock_freshness(record, now=self.now)
+        self.assertEqual(fresh["status"], issue_lock_store.STATUS_STALE_ABSOLUTE_CAP)
+        self.assertIn("re-adoption", fresh["reason"])
+
+    def test_heartbeat_lifecycle_without_a_heartbeat_fails_closed(self):
+        record = self.write_lock()
+        del record["work_lease"]["last_heartbeat_at"]
+        issue_lock_store.save_lock_file(self._path(), record)
+        fresh = issue_lock_store.assess_lock_freshness(record, now=self.now)
+        self.assertEqual(
+            fresh["status"], issue_lock_store.STATUS_STALE_MISSED_HEARTBEAT
+        )
+        self.assertIn("fail closed", fresh["reason"])
+
+    def test_absent_lock(self):
+        fresh = issue_lock_store.assess_lock_freshness(None)
+        self.assertEqual(fresh["status"], issue_lock_store.STATUS_ABSENT)
+        self.assertFalse(fresh["stale"])
+
+
+class TestLegacyLocksStayProtected(_LockFixture):
+    """AC-N8: deployment must not retroactively shorten an existing claim."""
+
+    def test_legacy_lock_with_a_stale_heartbeat_remains_live(self):
+        """The deployment-safety case.
+
+        A four-hour legacy lease minted three hours ago has not heartbeated
+        once. Under the new grace it would be long gone; under its preserved
+        absolute expiry it is still live, and must stay that way.
+        """
+        record = self.write_lock(
+            lifecycle=None,
+            created_delta=timedelta(hours=3),
+            heartbeat_delta=timedelta(hours=3),
+            expires_delta=timedelta(hours=1),
+        )
+        fresh = issue_lock_store.assess_lock_freshness(record, now=self.now)
+        self.assertEqual(fresh["status"], issue_lock_store.STATUS_LIVE)
+        self.assertTrue(fresh["live"])
+        self.assertTrue(fresh["legacy_lease"])
+        self.assertTrue(fresh["legacy_expiry_preserved"])
+
+    def test_legacy_lock_past_its_absolute_expiry_is_expired_as_before(self):
+        record = self.write_lock(
+            lifecycle=None,
+            created_delta=timedelta(hours=5),
+            heartbeat_delta=timedelta(hours=5),
+            expires_delta=timedelta(hours=-1),
+        )
+        fresh = issue_lock_store.assess_lock_freshness(record, now=self.now)
+        self.assertEqual(fresh["status"], issue_lock_store.STATUS_EXPIRED)
+
+    def test_legacy_lock_is_never_reclaimed_by_the_heartbeat_band(self):
+        record = self.write_lock(
+            lifecycle=None,
+            created_delta=timedelta(hours=3),
+            heartbeat_delta=timedelta(hours=3),
+            expires_delta=timedelta(hours=1),
+        )
+        reclaim = issue_lock_store.assess_expired_lock_reclaim(record, now=self.now)
+        self.assertFalse(reclaim["reclaim_allowed"])
+
+
+class TestReclaimAfterMissedHeartbeat(_LockFixture):
+    def test_missed_heartbeat_makes_ownership_reclaimable(self):
+        record = self.write_lock(
+            pid=os.getpid(),
+            heartbeat_delta=timedelta(minutes=15),
+            expires_delta=timedelta(hours=3),
+        )
+        reclaim = issue_lock_store.assess_expired_lock_reclaim(record, now=self.now)
+        self.assertTrue(reclaim["reclaim_allowed"])
+        self.assertIn("stale_missed_heartbeat", reclaim["reasons"][0])
+
+    def test_live_lease_is_never_reclaimable(self):
+        record = self.write_lock(heartbeat_delta=timedelta(minutes=1))
+        reclaim = issue_lock_store.assess_expired_lock_reclaim(record, now=self.now)
+        self.assertFalse(reclaim["reclaim_allowed"])
+
+    def test_dead_pid_reclaim_path_is_unchanged(self):
+        """#753 must keep working through its original conditions."""
+        record = self.write_lock(pid=DEAD_PID, heartbeat_delta=timedelta(minutes=1))
+        reclaim = issue_lock_store.assess_expired_lock_reclaim(record, now=self.now)
+        self.assertTrue(reclaim["reclaim_allowed"])
+        self.assertTrue(reclaim["owner_pid_dead"])
+
+
+class TestHeartbeatWriter(_LockFixture):
+    """A4: flock + CAS + exact verification, and no revival path."""
+
+    def _heartbeat(self, **kwargs):
+        params = {
+            "remote": REMOTE,
+            "org": ORG,
+            "repo": REPO,
+            "issue_number": ISSUE,
+            "branch_name": BRANCH,
+            "worktree_path": self.worktree,
+            "identity": IDENTITY,
+            "profile": PROFILE,
+            "task_session_id": "author_issue_work-aaaabbbbccccdddd",
+            "lock_dir": self.lock_dir.name,
+            "now": self.now,
+        }
+        params.update(kwargs)
+        return issue_lock_store.heartbeat_session_lock(**params)
+
+    def test_heartbeat_slides_expiry_and_advances_generation(self):
+        self.write_lock(heartbeat_delta=timedelta(minutes=4), generation=5)
+        result = self._heartbeat()
+        self.assertTrue(result["success"], result)
+        self.assertEqual(result["prior_generation"], 5)
+        self.assertEqual(result["lock_generation"], 6)
+        self.assertEqual(result["heartbeat_count"], 1)
+        self.assertEqual(result["last_heartbeat_at"], _ts(self.now))
+        self.assertEqual(result["expires_at"], _ts(self.now + timedelta(minutes=10)))
+        self.assertTrue(result["freshness"]["live"])
+
+    def test_heartbeat_is_durable_and_repeatable(self):
+        self.write_lock(heartbeat_delta=timedelta(minutes=4))
+        self._heartbeat()
+        second = self._heartbeat(now=self.now + timedelta(minutes=1))
+        self.assertTrue(second["success"], second)
+        self.assertEqual(second["heartbeat_count"], 2)
+        written = issue_lock_store.read_lock_file(self._path())
+        self.assertEqual(written["work_lease"]["heartbeat_count"], 2)
+
+    def test_stale_generation_is_refused(self):
+        self.write_lock(generation=5)
+        result = self._heartbeat(expected_generation=4)
+        self.assertFalse(result["success"])
+        self.assertIn("generation changed", result["reasons"][0])
+
+    def test_foreign_session_is_refused(self):
+        self.write_lock()
+        result = self._heartbeat(task_session_id="author_issue_work-ffffffffffffffff")
+        self.assertFalse(result["success"])
+        self.assertIn("task_session_id does not match", " ".join(result["reasons"]))
+
+    def test_missing_session_id_is_refused(self):
+        self.write_lock()
+        result = self._heartbeat(task_session_id="")
+        self.assertFalse(result["success"])
+
+    def test_foreign_claimant_is_refused(self):
+        self.write_lock()
+        for field, value in (
+            ("identity", "someone-else"),
+            ("profile", "other-profile"),
+        ):
+            with self.subTest(field=field):
+                result = self._heartbeat(**{field: value})
+                self.assertFalse(result["success"])
+
+    def test_branch_and_worktree_mismatch_are_refused(self):
+        self.write_lock()
+        wrong_branch = self._heartbeat(branch_name=f"fix/issue-{ISSUE}-other")
+        self.assertFalse(wrong_branch["success"])
+        wrong_worktree = self._heartbeat(worktree_path="/tmp/not-the-worktree")
+        self.assertFalse(wrong_worktree["success"])
+
+    def test_lapsed_lease_cannot_be_heartbeated_back_to_life(self):
+        """No revival path (A4).
+
+        A session that stopped proving liveness must reclaim under a fresh
+        generation, not restore ownership retroactively.
+        """
+        self.write_lock(
+            heartbeat_delta=timedelta(minutes=30), expires_delta=timedelta(hours=1)
+        )
+        result = self._heartbeat()
+        self.assertFalse(result["success"])
+        self.assertIn("reclaimed", " ".join(result["reasons"]))
+
+    def test_absent_lock_cannot_be_created_by_heartbeat(self):
+        result = self._heartbeat()
+        self.assertFalse(result["success"])
+        self.assertIn("no durable lock", result["reasons"][0])
+
+    def test_legacy_lock_is_refused_until_rebound(self):
+        self.write_lock(lifecycle=None)
+        result = self._heartbeat()
+        self.assertFalse(result["success"])
+        self.assertTrue(result["legacy_lease"])
+        self.assertIn("rebound", " ".join(result["reasons"]))
+
+
+class TestLegacyRebind(_LockFixture):
+    """AC-N8 exit route: canonical exact-owner rebinding."""
+
+    def _rebind(self, **kwargs):
+        params = {
+            "remote": REMOTE,
+            "org": ORG,
+            "repo": REPO,
+            "issue_number": ISSUE,
+            "branch_name": BRANCH,
+            "worktree_path": self.worktree,
+            "identity": IDENTITY,
+            "profile": PROFILE,
+            "lock_dir": self.lock_dir.name,
+            "now": self.now,
+        }
+        params.update(kwargs)
+        return issue_lock_store.rebind_legacy_lock(**params)
+
+    def test_rebind_mints_a_session_and_a_genuine_first_heartbeat(self):
+        self.write_lock(
+            lifecycle=None,
+            created_delta=timedelta(hours=3),
+            heartbeat_delta=timedelta(hours=3),
+            expires_delta=timedelta(hours=1),
+            generation=2,
+        )
+        result = self._rebind()
+        self.assertTrue(result["success"], result)
+        self.assertTrue(result["task_session_id"])
+        self.assertEqual(result["lock_generation"], 3)
+
+        written = issue_lock_store.read_lock_file(self._path())
+        lease = written["work_lease"]
+        self.assertEqual(
+            lease["lifecycle_version"], lease_policy.LIFECYCLE_HEARTBEAT_V1
+        )
+        self.assertEqual(lease["last_heartbeat_at"], _ts(self.now))
+        self.assertEqual(lease["expires_at"], _ts(self.now + timedelta(minutes=10)))
+        self.assertFalse(issue_lock_store.is_legacy_lease(written))
+        # The original claim is preserved for audit rather than overwritten.
+        origin = written["legacy_rebind"]["legacy_origin"]
+        self.assertTrue(origin["created_at"])
+        self.assertEqual(origin["lifecycle"], lease_policy.LIFECYCLE_LEGACY)
+
+    def test_rebound_lock_can_then_heartbeat(self):
+        self.write_lock(
+            lifecycle=None,
+            created_delta=timedelta(hours=3),
+            heartbeat_delta=timedelta(hours=3),
+            expires_delta=timedelta(hours=1),
+        )
+        rebound = self._rebind()
+        beat = issue_lock_store.heartbeat_session_lock(
+            remote=REMOTE,
+            org=ORG,
+            repo=REPO,
+            issue_number=ISSUE,
+            branch_name=BRANCH,
+            worktree_path=self.worktree,
+            identity=IDENTITY,
+            profile=PROFILE,
+            task_session_id=rebound["task_session_id"],
+            lock_dir=self.lock_dir.name,
+            now=self.now + timedelta(minutes=1),
+        )
+        self.assertTrue(beat["success"], beat)
+
+    def test_rebind_refuses_a_foreign_owner(self):
+        self.write_lock(lifecycle=None, expires_delta=timedelta(hours=1))
+        result = self._rebind(identity="someone-else")
+        self.assertFalse(result["success"])
+
+    def test_rebind_refuses_a_lock_already_on_the_lifecycle(self):
+        self.write_lock()
+        result = self._rebind()
+        self.assertFalse(result["success"])
+        self.assertFalse(result["legacy_lease"])
+
+    def test_rebind_is_not_a_recovery_path_for_a_lapsed_legacy_lease(self):
+        """An expired legacy lease belongs to #760 renewal or #601 reclaim."""
+        self.write_lock(
+            lifecycle=None,
+            created_delta=timedelta(hours=5),
+            heartbeat_delta=timedelta(hours=5),
+            expires_delta=timedelta(hours=-1),
+        )
+        result = self._rebind()
+        self.assertFalse(result["success"])
+        self.assertIn("not a recovery path", " ".join(result["reasons"]))
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_issue_794_conflict_gate_reclaim.py

@@ -0,0 +1,193 @@
+"""Conflict gate honors heartbeat-lifecycle non-live reclaim bands (#790 review #502/#516).
+
+``assess_expired_lock_reclaim`` already permits reclaim for the heartbeat-lifecycle
+stale bands (``stale_missed_heartbeat``, ``stale_absolute_cap``) without a dead PID.
+But ``assess_same_issue_lease_conflict`` used to enter that reclaim branch only under
+``is_lease_expired`` (``expires_at <= now``). For a heartbeat-lifecycle lease that is
+non-live yet whose ``expires_at`` is still in the future, the acquisition gate fell
+through to the foreign "already has an active lease" block and never consulted the
+reclaim assessor — so the load-bearing heartbeat was not load-bearing for foreign
+reclaim, the exact abandonment scenario #790 exists to fix.
+
+Two future-``expires_at`` non-live shapes are reachable:
+
+* ``stale_absolute_cap`` — a session that keeps heartbeating past the 8h absolute cap
+  has ``expires_at = last_heartbeat + TTL`` in the future (default policy).
+* ``stale_missed_heartbeat`` — under an independent TTL>grace policy the heartbeat
+  grace lapses while ``expires_at`` is still ahead.
+
+These tests pin: both reclaim from a foreign acquirer; a live lease still blocks a
+foreign acquirer; the same owner may reclaim its own abandoned heartbeat lease; and a
+legacy (pre-lifecycle) lock keeps its absolute-``expires_at`` clock — a non-expired
+legacy lock with a dead PID is *not* reclaimable through this path.
+"""
+
+from __future__ import annotations
+
+import os
+import sys
+import unittest
+from datetime import datetime, timedelta, timezone
+from unittest import mock
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+import issue_lock_store as ils  # noqa: E402
+import lease_policy  # noqa: E402
+
+ISSUE = 790
+OWNER_BRANCH = f"fix/issue-{ISSUE}-slice-a-heartbeat-policy"
+OWNER_WORKTREE = "/tmp/wt-790-owner"
+FOREIGN_BRANCH = f"fix/issue-{ISSUE}-foreign-attempt"
+FOREIGN_WORKTREE = "/tmp/wt-790-foreign"
+
+
+def _ts(moment: datetime) -> str:
+    return (
+        moment.astimezone(timezone.utc)
+        .replace(microsecond=0)
+        .isoformat()
+        .replace("+00:00", "Z")
+    )
+
+
+class _ConflictGateBase(unittest.TestCase):
+    def setUp(self):
+        self.now = datetime(2026, 7, 23, 12, 0, 0, tzinfo=timezone.utc)
+
+    def _lock(
+        self,
+        *,
+        lifecycle: str | None,
+        created_ago: timedelta,
+        heartbeat_ago: timedelta,
+        expires_in: timedelta,
+        pid: int,
+    ) -> dict:
+        lease: dict = {
+            "operation_type": ils.AUTHOR_ISSUE_WORK_LEASE,
+            "issue_number": ISSUE,
+            "branch": OWNER_BRANCH,
+            "worktree_path": OWNER_WORKTREE,
+            "created_at": _ts(self.now - created_ago),
+            "last_heartbeat_at": _ts(self.now - heartbeat_ago),
+            "expires_at": _ts(self.now + expires_in),
+        }
+        if lifecycle is not None:
+            lease["lifecycle_version"] = lifecycle
+            lease["task_session_id"] = "author_issue_work-deadbeefdeadbeef"
+        return {
+            "issue_number": ISSUE,
+            "branch_name": OWNER_BRANCH,
+            "remote": "prgs",
+            "org": "Scaled-Tech-Consulting",
+            "repo": "Gitea-Tools",
+            "worktree_path": OWNER_WORKTREE,
+            "session_pid": pid,
+            "pid": pid,
+            "work_lease": lease,
+        }
+
+    def _foreign_conflict(self, existing: dict) -> str | None:
+        return ils.assess_same_issue_lease_conflict(
+            existing,
+            issue_number=ISSUE,
+            branch_name=FOREIGN_BRANCH,
+            worktree_path=FOREIGN_WORKTREE,
+            now=self.now,
+        )
+
+    def _same_owner_conflict(self, existing: dict) -> str | None:
+        return ils.assess_same_issue_lease_conflict(
+            existing,
+            issue_number=ISSUE,
+            branch_name=OWNER_BRANCH,
+            worktree_path=OWNER_WORKTREE,
+            now=self.now,
+        )
+
+
+class TestHeartbeatNonLiveFutureExpiresReclaim(_ConflictGateBase):
+    def test_stale_absolute_cap_future_expires_allows_foreign_reclaim(self):
+        # Created >8h ago, heartbeated one minute ago, expires 9 min in the FUTURE,
+        # owner PID alive: freshness = stale_absolute_cap, live=False, not expired.
+        existing = self._lock(
+            lifecycle=lease_policy.LIFECYCLE_HEARTBEAT_V1,
+            created_ago=timedelta(hours=9),
+            heartbeat_ago=timedelta(minutes=1),
+            expires_in=timedelta(minutes=9),
+            pid=os.getpid(),
+        )
+        freshness = ils.assess_lock_freshness(existing, now=self.now)
+        self.assertEqual(freshness["status"], ils.STATUS_STALE_ABSOLUTE_CAP)
+        self.assertFalse(freshness["live"])
+        self.assertFalse(ils.is_lease_expired(existing, now=self.now))
+        with mock.patch.object(ils, "is_process_alive", return_value=True):
+            self.assertIsNone(self._foreign_conflict(existing))
+
+    def test_missed_heartbeat_ttl_gt_grace_future_expires_allows_foreign_reclaim(self):
+        # Heartbeat grace (default 10 min) lapsed 5 min ago, but a TTL>grace policy
+        # leaves expires_at 20 min in the FUTURE: stale_missed_heartbeat, not expired.
+        existing = self._lock(
+            lifecycle=lease_policy.LIFECYCLE_HEARTBEAT_V1,
+            created_ago=timedelta(minutes=30),
+            heartbeat_ago=timedelta(minutes=15),
+            expires_in=timedelta(minutes=20),
+            pid=os.getpid(),
+        )
+        freshness = ils.assess_lock_freshness(existing, now=self.now)
+        self.assertEqual(freshness["status"], ils.STATUS_STALE_MISSED_HEARTBEAT)
+        self.assertFalse(freshness["live"])
+        self.assertFalse(ils.is_lease_expired(existing, now=self.now))
+        with mock.patch.object(ils, "is_process_alive", return_value=True):
+            self.assertIsNone(self._foreign_conflict(existing))
+
+    def test_same_owner_may_reclaim_its_own_abandoned_heartbeat_lease(self):
+        existing = self._lock(
+            lifecycle=lease_policy.LIFECYCLE_HEARTBEAT_V1,
+            created_ago=timedelta(hours=9),
+            heartbeat_ago=timedelta(minutes=1),
+            expires_in=timedelta(minutes=9),
+            pid=os.getpid(),
+        )
+        with mock.patch.object(ils, "is_process_alive", return_value=True):
+            self.assertIsNone(self._same_owner_conflict(existing))
+
+
+class TestLiveAndLegacyStillBlockForeign(_ConflictGateBase):
+    def test_live_heartbeat_lease_still_blocks_foreign(self):
+        existing = self._lock(
+            lifecycle=lease_policy.LIFECYCLE_HEARTBEAT_V1,
+            created_ago=timedelta(minutes=5),
+            heartbeat_ago=timedelta(minutes=1),
+            expires_in=timedelta(minutes=9),
+            pid=os.getpid(),
+        )
+        freshness = ils.assess_lock_freshness(existing, now=self.now)
+        self.assertTrue(freshness["live"])
+        with mock.patch.object(ils, "is_process_alive", return_value=True):
+            block = self._foreign_conflict(existing)
+        self.assertIn("already has an active", block or "")
+
+    def test_legacy_lease_future_expires_dead_pid_is_not_reclaimed_here(self):
+        # AC-N8: a legacy lock keeps its absolute expires_at clock. Non-expired +
+        # dead PID is non-live, but the widened band excludes legacy, so the
+        # foreign acquirer is still blocked rather than silently reclaiming.
+        existing = self._lock(
+            lifecycle=None,
+            created_ago=timedelta(hours=9),
+            heartbeat_ago=timedelta(hours=9),
+            expires_in=timedelta(hours=2),
+            pid=4_194_304,  # far above any live pid on a test host
+        )
+        with mock.patch.object(ils, "is_process_alive", return_value=False):
+            freshness = ils.assess_lock_freshness(existing, now=self.now)
+            self.assertTrue(freshness["legacy_lease"])
+            self.assertFalse(freshness["live"])
+            self.assertFalse(ils.is_lease_expired(existing, now=self.now))
+            block = self._foreign_conflict(existing)
+        self.assertIn("already has an active", block or "")
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_webui_analytics.py

@@ -0,0 +1,252 @@
+"""Unit and integration tests for Model Usage & Performance Analytics (#651)."""
+
+from __future__ import annotations
+
+import os
+import tempfile
+import unittest
+from starlette.testclient import TestClient
+
+import control_plane_db
+from webui.analytics_loader import (
+    ANALYTICS_SCHEMA_VERSION,
+    compute_percentile,
+    load_analytics,
+    record_usage,
+)
+from webui.app import create_app
+from webui import console_redaction
+
+
+class AnalyticsLoaderTest(unittest.TestCase):
+
+    def setUp(self) -> None:
+        self.temp_dir = tempfile.TemporaryDirectory()
+        self.db_path = os.path.join(self.temp_dir.name, "test_control_plane.sqlite3")
+        os.environ["GITEA_CONTROL_PLANE_DB"] = self.db_path
+        self.db = control_plane_db.ControlPlaneDB(db_path=self.db_path)
+
+    def tearDown(self) -> None:
+        self.temp_dir.cleanup()
+
+    def test_compute_percentile(self) -> None:
+        self.assertIsNone(compute_percentile([], 50.0))
+        self.assertEqual(compute_percentile([100], 50.0), 100.0)
+
+        # 2 elements: [100, 200]
+        self.assertEqual(compute_percentile([100, 200], 50.0), 150.0)
+
+        # 100 elements: 1..100
+        vals = list(range(1, 101))
+        self.assertEqual(compute_percentile(vals, 50.0), 50.5)
+        self.assertAlmostEqual(compute_percentile(vals, 90.0), 90.1)
+
+    def test_record_and_aggregate_usage(self) -> None:
+        # Record event 1 (complete data)
+        u1 = record_usage(
+            db_path=self.db_path,
+            remote="dadeschools",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            role="author",
+            model="gemini-3.6-flash",
+            issue_number=651,
+            stage="implementation",
+            input_tokens=1000,
+            output_tokens=500,
+            estimated_cost_usd=0.0015,
+            latency_ms=200,
+            duration_ms=3000,
+            metadata={"secret_key": "secret123", "note": "token=secret123"},
+        )
+        self.assertGreater(u1, 0)
+
+        # Record event 2 (missing tokens and cost -> unknown)
+        u2 = record_usage(
+            db_path=self.db_path,
+            remote="dadeschools",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            role="reviewer",
+            model="claude-3-5-sonnet",
+            pr_number=846,
+            stage="review",
+            latency_ms=500,
+            duration_ms=6000,
+        )
+        self.assertGreater(u2, u1)
+
+        snapshot = load_analytics(
+            db_path=self.db_path,
+            remote="dadeschools",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+        )
+
+        self.assertTrue(snapshot.ok)
+        self.assertEqual(snapshot.schema_version, ANALYTICS_SCHEMA_VERSION)
+        self.assertEqual(snapshot.total_events, 2)
+
+        # Verify overall summary
+        summary = snapshot.overall_summary
+        self.assertEqual(summary.total_events, 2)
+        self.assertEqual(summary.events_with_tokens, 1)
+        self.assertEqual(summary.total_tokens, 1500)
+        self.assertEqual(summary.events_with_cost, 1)
+        self.assertEqual(summary.estimated_cost_usd, 0.0015)
+        self.assertEqual(summary.events_with_latency, 2)
+        self.assertEqual(summary.latency_p50_ms, 350.0)
+
+        # Verify missing data handling (AC 3: not zero-fabricated)
+        reviewer_model = snapshot.by_model.get("claude-3-5-sonnet")
+        self.assertIsNotNone(reviewer_model)
+        self.assertEqual(reviewer_model.total_events, 1)
+        self.assertEqual(reviewer_model.events_with_tokens, 0)
+        self.assertIsNone(reviewer_model.total_tokens)
+        self.assertEqual(reviewer_model.display_tokens, "Unknown")
+        self.assertEqual(reviewer_model.events_with_cost, 0)
+        self.assertIsNone(reviewer_model.estimated_cost_usd)
+        self.assertEqual(reviewer_model.display_cost, "Unknown")
+
+        # Verify redaction (AC 4)
+        e1 = [e for e in snapshot.events if e.usage_id == u1][0]
+        self.assertIsNotNone(e1.metadata)
+        self.assertNotIn("secret123", e1.metadata)
+        self.assertIn("[REDACTED]", e1.metadata)
+
+    def test_missing_db_fail_soft(self) -> None:
+        invalid_path = "/nonexistent_path_dir/db.sqlite3"
+        snapshot = load_analytics(db_path=invalid_path)
+        self.assertFalse(snapshot.ok)
+        self.assertIn("control_plane_db_unavailable", snapshot.reason)
+        self.assertEqual(snapshot.overall_summary.display_tokens, "Unknown")
+
+
+class AnalyticsWebUITest(unittest.TestCase):
+
+    def setUp(self) -> None:
+        self.temp_dir = tempfile.TemporaryDirectory()
+        self.db_path = os.path.join(self.temp_dir.name, "test_webui.sqlite3")
+        os.environ["GITEA_CONTROL_PLANE_DB"] = self.db_path
+        self.app = create_app()
+        self.client = TestClient(self.app)
+
+        record_usage(
+            db_path=self.db_path,
+            remote="dadeschools",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            role="author",
+            model="gemini-3.6-flash",
+            issue_number=651,
+            stage="implementation",
+            input_tokens=2000,
+            output_tokens=1000,
+            estimated_cost_usd=0.003,
+            latency_ms=150,
+            duration_ms=2500,
+        )
+
+    def tearDown(self) -> None:
+        self.temp_dir.cleanup()
+
+    def test_analytics_html_route(self) -> None:
+        response = self.client.get("/analytics")
+        self.assertEqual(response.status_code, 200)
+        self.assertIn("Model Usage & Performance Analytics", response.text)
+        self.assertIn("gemini-3.6-flash", response.text)
+        self.assertIn("3,000", response.text)
+
+    def test_analytics_api_route(self) -> None:
+        response = self.client.get("/api/v1/analytics")
+        self.assertEqual(response.status_code, 200)
+        data = response.json()
+        self.assertTrue(data["ok"])
+        self.assertEqual(data["total_events"], 1)
+        self.assertIn("gemini-3.6-flash", data["by_model"])
+
+    def test_analytics_ingest_unauthorized_denied(self) -> None:
+        """F2: unauthenticated POST must not write the control-plane DB."""
+        payload = {
+            "remote": "dadeschools",
+            "org": "Scaled-Tech-Consulting",
+            "repo": "Gitea-Tools",
+            "role": "reviewer",
+            "model": "claude-3-5-sonnet",
+            "pr_number": 846,
+            "stage": "review",
+            "input_tokens": 500,
+            "output_tokens": 100,
+            "latency_ms": 400,
+            "metadata": "Review note token=secret456",
+        }
+        response = self.client.post("/api/v1/analytics/usage", json=payload)
+        self.assertEqual(response.status_code, 403)
+        res_json = response.json()
+        self.assertFalse(res_json.get("ok", True))
+        self.assertEqual(res_json.get("error"), "unauthorized")
+        authorization = res_json.get("authorization") or {}
+        self.assertFalse(authorization.get("allowed"))
+        self.assertFalse(authorization.get("execution_enabled"))
+
+        # No new row written
+        res2 = self.client.get("/api/v1/analytics")
+        self.assertEqual(res2.status_code, 200)
+        self.assertEqual(res2.json()["total_events"], 1)
+
+    def test_html_escapes_script_bearing_model_role_stage(self) -> None:
+        """F1: stored XSS — dynamic model/role/stage must render escaped."""
+        xss = '<script>alert(1)</script>'
+        record_usage(
+            db_path=self.db_path,
+            remote="dadeschools",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            role=xss,
+            model=xss,
+            stage=xss,
+            issue_number=999,
+            status="success",
+        )
+        response = self.client.get("/analytics")
+        self.assertEqual(response.status_code, 200)
+        # Raw tag must not appear; escaped form must.
+        self.assertNotIn("<script>alert(1)</script>", response.text)
+        self.assertIn("&lt;script&gt;alert(1)&lt;/script&gt;", response.text)
+
+    def test_load_analytics_coerces_none_scope(self) -> None:
+        """F4: None remote/org/repo become empty strings, never None."""
+        snapshot = load_analytics(db_path=self.db_path, remote=None, org=None, repo=None)
+        self.assertIsInstance(snapshot.remote, str)
+        self.assertIsInstance(snapshot.org, str)
+        self.assertIsInstance(snapshot.repo, str)
+        self.assertEqual(snapshot.remote, "")
+        self.assertEqual(snapshot.org, "")
+        self.assertEqual(snapshot.repo, "")
+
+    def test_usage_events_retention_max_rows(self) -> None:
+        """F3: record_usage_event enforces USAGE_EVENTS_MAX_ROWS."""
+        db = control_plane_db.ControlPlaneDB(db_path=self.db_path)
+        original_max = db.USAGE_EVENTS_MAX_ROWS
+        try:
+            db.USAGE_EVENTS_MAX_ROWS = 3
+            for i in range(5):
+                db.record_usage_event(
+                    remote="dadeschools",
+                    org="org",
+                    repo="repo",
+                    role="author",
+                    model=f"model-{i}",
+                    stage="test",
+                )
+            rows = db.query_usage_events(limit=100)
+            self.assertLessEqual(len(rows), 3)
+            # Newest three retained
+            models = {r["model"] for r in rows}
+            self.assertEqual(models, {"model-2", "model-3", "model-4"})
+        finally:
+            db.USAGE_EVENTS_MAX_ROWS = original_max
+
+
+if __name__ == "__main__":
+    unittest.main()

webui/analytics_loader.py

@@ -0,0 +1,433 @@
+"""Model usage, token cost, latency, and workflow-performance analytics (#651, Phase 4).
+
+Ingests session instrumentation metrics, aggregates usage/cost/latency percentiles
+by project, role, model, issue/PR, and stage, enforcing secret redaction and
+explicitly rendering missing metrics as "Unknown" without zero-fabrication.
+"""
+
+from __future__ import annotations
+
+import math
+from dataclasses import asdict, dataclass
+from typing import Any, Sequence
+
+import control_plane_db
+from webui import console_redaction
+
+ANALYTICS_SCHEMA_VERSION = 1
+
+
+@dataclass(frozen=True)
+class UsageEvent:
+    usage_id: int
+    session_id: str | None
+    remote: str
+    org: str
+    repo: str
+    project_id: str | None
+    role: str
+    model: str
+    issue_number: int | None
+    pr_number: int | None
+    stage: str
+    input_tokens: int | None
+    output_tokens: int | None
+    total_tokens: int | None
+    estimated_cost_usd: float | None
+    latency_ms: int | None
+    duration_ms: int | None
+    status: str
+    metadata: str | None
+    created_at: str
+
+    def to_dict(self) -> dict[str, Any]:
+        d = asdict(self)
+        if d["metadata"]:
+            d["metadata"] = console_redaction.redact_text(d["metadata"])
+        return d
+
+
+@dataclass(frozen=True)
+class GroupMetrics:
+    name: str
+    total_events: int
+    events_with_tokens: int
+    input_tokens: int | None
+    output_tokens: int | None
+    total_tokens: int | None
+    events_with_cost: int
+    estimated_cost_usd: float | None
+    events_with_latency: int
+    latency_p50_ms: float | None
+    latency_p90_ms: float | None
+    latency_p95_ms: float | None
+    latency_p99_ms: float | None
+    latency_avg_ms: float | None
+    events_with_duration: int
+    duration_avg_ms: float | None
+    display_tokens: str
+    display_cost: str
+    display_latency_p50: str
+    display_latency_p90: str
+    display_duration_avg: str
+
+    def to_dict(self) -> dict[str, Any]:
+        return asdict(self)
+
+
+@dataclass(frozen=True)
+class AnalyticsSnapshot:
+    ok: bool
+    reason: str
+    schema_version: int
+    remote: str
+    org: str
+    repo: str
+    total_events: int
+    overall_summary: GroupMetrics
+    by_project: dict[str, GroupMetrics]
+    by_role: dict[str, GroupMetrics]
+    by_model: dict[str, GroupMetrics]
+    by_work_item: dict[str, GroupMetrics]
+    by_stage: dict[str, GroupMetrics]
+    events: tuple[UsageEvent, ...]
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "ok": self.ok,
+            "reason": self.reason,
+            "schema_version": self.schema_version,
+            "remote": self.remote,
+            "org": self.org,
+            "repo": self.repo,
+            "total_events": self.total_events,
+            "overall_summary": self.overall_summary.to_dict(),
+            "by_project": {k: v.to_dict() for k, v in self.by_project.items()},
+            "by_role": {k: v.to_dict() for k, v in self.by_role.items()},
+            "by_model": {k: v.to_dict() for k, v in self.by_model.items()},
+            "by_work_item": {k: v.to_dict() for k, v in self.by_work_item.items()},
+            "by_stage": {k: v.to_dict() for k, v in self.by_stage.items()},
+            "events": [e.to_dict() for e in self.events],
+        }
+
+
+def compute_percentile(values: Sequence[float | int], percentile: float) -> float | None:
+    if not values:
+        return None
+    sorted_vals = sorted(values)
+    n = len(sorted_vals)
+    if n == 1:
+        return float(sorted_vals[0])
+    k = (n - 1) * (percentile / 100.0)
+    f = math.floor(k)
+    c = math.ceil(k)
+    if f == c:
+        return float(sorted_vals[int(f)])
+    d0 = sorted_vals[int(f)] * (c - k)
+    d1 = sorted_vals[int(c)] * (k - f)
+    return float(d0 + d1)
+
+
+def aggregate_events(group_name: str, events: Sequence[UsageEvent]) -> GroupMetrics:
+    total_events = len(events)
+    if total_events == 0:
+        return GroupMetrics(
+            name=group_name,
+            total_events=0,
+            events_with_tokens=0,
+            input_tokens=None,
+            output_tokens=None,
+            total_tokens=None,
+            events_with_cost=0,
+            estimated_cost_usd=None,
+            events_with_latency=0,
+            latency_p50_ms=None,
+            latency_p90_ms=None,
+            latency_p95_ms=None,
+            latency_p99_ms=None,
+            latency_avg_ms=None,
+            events_with_duration=0,
+            duration_avg_ms=None,
+            display_tokens="Unknown",
+            display_cost="Unknown",
+            display_latency_p50="Unknown",
+            display_latency_p90="Unknown",
+            display_duration_avg="Unknown",
+        )
+
+    token_events = [
+        e for e in events
+        if e.total_tokens is not None or e.input_tokens is not None or e.output_tokens is not None
+    ]
+    events_with_tokens = len(token_events)
+    if events_with_tokens > 0:
+        input_tokens = sum(e.input_tokens or 0 for e in token_events)
+        output_tokens = sum(e.output_tokens or 0 for e in token_events)
+        total_tokens = sum(
+            e.total_tokens if e.total_tokens is not None else ((e.input_tokens or 0) + (e.output_tokens or 0))
+            for e in token_events
+        )
+        display_tokens = f"{total_tokens:,}"
+    else:
+        input_tokens = None
+        output_tokens = None
+        total_tokens = None
+        display_tokens = "Unknown"
+
+    cost_events = [e for e in events if e.estimated_cost_usd is not None]
+    events_with_cost = len(cost_events)
+    if events_with_cost > 0:
+        estimated_cost_usd = round(sum(e.estimated_cost_usd for e in cost_events), 6)
+        display_cost = f"${estimated_cost_usd:.4f}"
+    else:
+        estimated_cost_usd = None
+        display_cost = "Unknown"
+
+    latency_vals = [e.latency_ms for e in events if e.latency_ms is not None]
+    events_with_latency = len(latency_vals)
+    if events_with_latency > 0:
+        latency_p50_ms = compute_percentile(latency_vals, 50.0)
+        latency_p90_ms = compute_percentile(latency_vals, 90.0)
+        latency_p95_ms = compute_percentile(latency_vals, 95.0)
+        latency_p99_ms = compute_percentile(latency_vals, 99.0)
+        latency_avg_ms = round(sum(latency_vals) / events_with_latency, 2)
+        display_latency_p50 = f"{round(latency_p50_ms, 1)} ms" if latency_p50_ms is not None else "Unknown"
+        display_latency_p90 = f"{round(latency_p90_ms, 1)} ms" if latency_p90_ms is not None else "Unknown"
+    else:
+        latency_p50_ms = None
+        latency_p90_ms = None
+        latency_p95_ms = None
+        latency_p99_ms = None
+        latency_avg_ms = None
+        display_latency_p50 = "Unknown"
+        display_latency_p90 = "Unknown"
+
+    duration_vals = [e.duration_ms for e in events if e.duration_ms is not None]
+    events_with_duration = len(duration_vals)
+    if events_with_duration > 0:
+        duration_avg_ms = round(sum(duration_vals) / events_with_duration, 2)
+        display_duration_avg = f"{round(duration_avg_ms / 1000.0, 2)} s" if duration_avg_ms >= 1000 else f"{round(duration_avg_ms, 1)} ms"
+    else:
+        duration_avg_ms = None
+        display_duration_avg = "Unknown"
+
+    return GroupMetrics(
+        name=group_name,
+        total_events=total_events,
+        events_with_tokens=events_with_tokens,
+        input_tokens=input_tokens,
+        output_tokens=output_tokens,
+        total_tokens=total_tokens,
+        events_with_cost=events_with_cost,
+        estimated_cost_usd=estimated_cost_usd,
+        events_with_latency=events_with_latency,
+        latency_p50_ms=latency_p50_ms,
+        latency_p90_ms=latency_p90_ms,
+        latency_p95_ms=latency_p95_ms,
+        latency_p99_ms=latency_p99_ms,
+        latency_avg_ms=latency_avg_ms,
+        events_with_duration=events_with_duration,
+        duration_avg_ms=duration_avg_ms,
+        display_tokens=display_tokens,
+        display_cost=display_cost,
+        display_latency_p50=display_latency_p50,
+        display_latency_p90=display_latency_p90,
+        display_duration_avg=display_duration_avg,
+    )
+
+
+def record_usage(
+    *,
+    db_path: str | None = None,
+    session_id: str | None = None,
+    remote: str = "dadeschools",
+    org: str = "",
+    repo: str = "",
+    project_id: str | None = None,
+    role: str = "unknown",
+    model: str = "unknown",
+    issue_number: int | None = None,
+    pr_number: int | None = None,
+    stage: str = "unknown",
+    input_tokens: int | None = None,
+    output_tokens: int | None = None,
+    total_tokens: int | None = None,
+    estimated_cost_usd: float | None = None,
+    latency_ms: int | None = None,
+    duration_ms: int | None = None,
+    status: str = "success",
+    metadata: str | dict[str, Any] | None = None,
+    created_at: str | None = None,
+) -> int:
+    """Ingest/record a single usage event with optional metrics."""
+    db = control_plane_db.ControlPlaneDB(db_path=db_path)
+    return db.record_usage_event(
+        session_id=session_id,
+        remote=remote,
+        org=org,
+        repo=repo,
+        project_id=project_id,
+        role=role,
+        model=model,
+        issue_number=issue_number,
+        pr_number=pr_number,
+        stage=stage,
+        input_tokens=input_tokens,
+        output_tokens=output_tokens,
+        total_tokens=total_tokens,
+        estimated_cost_usd=estimated_cost_usd,
+        latency_ms=latency_ms,
+        duration_ms=duration_ms,
+        status=status,
+        metadata=metadata,
+        created_at=created_at,
+    )
+
+
+def load_analytics(
+    *,
+    db_path: str | None = None,
+    remote: str | None = None,
+    org: str | None = None,
+    repo: str | None = None,
+    project_id: str | None = None,
+    role: str | None = None,
+    model: str | None = None,
+    stage: str | None = None,
+    issue_number: int | None = None,
+    pr_number: int | None = None,
+    limit: int = 500,
+) -> AnalyticsSnapshot:
+    """Load analytics snapshot aggregated by project, role, model, issue/PR, and stage."""
+    remote_filter = (remote or "").strip() or None
+    org_filter = (org or "").strip() or None
+    repo_filter = (repo or "").strip() or None
+    role_filter = (role or "").strip() or None
+    model_filter = (model or "").strip() or None
+    stage_filter = (stage or "").strip() or None
+
+    # F4: coerce optional scope filters to str so AnalyticsSnapshot never holds None.
+    scope_remote = (remote or "").strip()
+    scope_org = (org or "").strip()
+    scope_repo = (repo or "").strip()
+
+    try:
+        db = control_plane_db.ControlPlaneDB(db_path=db_path)
+        rows = db.query_usage_events(
+            remote=remote_filter,
+            org=org_filter,
+            repo=repo_filter,
+            project_id=project_id,
+            role=role_filter,
+            model=model_filter,
+            stage=stage_filter,
+            issue_number=issue_number,
+            pr_number=pr_number,
+            limit=limit,
+        )
+    except Exception as exc:
+        empty_summary = aggregate_events("Overall", [])
+        return AnalyticsSnapshot(
+            ok=False,
+            reason=f"control_plane_db_unavailable: {exc}",
+            schema_version=ANALYTICS_SCHEMA_VERSION,
+            remote=scope_remote,
+            org=scope_org,
+            repo=scope_repo,
+            total_events=0,
+            overall_summary=empty_summary,
+            by_project={},
+            by_role={},
+            by_model={},
+            by_work_item={},
+            by_stage={},
+            events=(),
+        )
+
+    parsed_events: list[UsageEvent] = []
+    for r in rows:
+        meta = console_redaction.redact_text(r.get("metadata")) if r.get("metadata") else None
+        parsed_events.append(
+            UsageEvent(
+                usage_id=r["usage_id"],
+                session_id=r.get("session_id"),
+                remote=r.get("remote") or scope_remote,
+                org=r.get("org") or scope_org,
+                repo=r.get("repo") or scope_repo,
+                project_id=r.get("project_id"),
+                role=r.get("role") or "unknown",
+                model=r.get("model") or "unknown",
+                issue_number=r.get("issue_number"),
+                pr_number=r.get("pr_number"),
+                stage=r.get("stage") or "unknown",
+                input_tokens=r.get("input_tokens"),
+                output_tokens=r.get("output_tokens"),
+                total_tokens=r.get("total_tokens"),
+                estimated_cost_usd=r.get("estimated_cost_usd"),
+                latency_ms=r.get("latency_ms"),
+                duration_ms=r.get("duration_ms"),
+                status=r.get("status") or "success",
+                metadata=meta,
+                created_at=r.get("created_at") or "",
+            )
+        )
+
+    overall_summary = aggregate_events("Overall", parsed_events)
+
+    # Group by project
+    groups_by_project: dict[str, list[UsageEvent]] = {}
+    for e in parsed_events:
+        key = e.project_id or (f"{e.org}/{e.repo}" if e.org and e.repo else "default")
+        groups_by_project.setdefault(key, []).append(e)
+    by_project = {k: aggregate_events(k, v) for k, v in groups_by_project.items()}
+
+    # Group by role
+    groups_by_role: dict[str, list[UsageEvent]] = {}
+    for e in parsed_events:
+        groups_by_role.setdefault(e.role, []).append(e)
+    by_role = {k: aggregate_events(k, v) for k, v in groups_by_role.items()}
+
+    # Group by model
+    groups_by_model: dict[str, list[UsageEvent]] = {}
+    for e in parsed_events:
+        groups_by_model.setdefault(e.model, []).append(e)
+    by_model = {k: aggregate_events(k, v) for k, v in groups_by_model.items()}
+
+    # Group by work item
+    groups_by_work_item: dict[str, list[UsageEvent]] = {}
+    for e in parsed_events:
+        if e.issue_number:
+            key = f"issue #{e.issue_number}"
+        elif e.pr_number:
+            key = f"pr #{e.pr_number}"
+        else:
+            key = "unlinked"
+        groups_by_work_item.setdefault(key, []).append(e)
+    by_work_item = {k: aggregate_events(k, v) for k, v in groups_by_work_item.items()}
+
+    # Group by stage
+    groups_by_stage: dict[str, list[UsageEvent]] = {}
+    for e in parsed_events:
+        groups_by_stage.setdefault(e.stage, []).append(e)
+    by_stage = {k: aggregate_events(k, v) for k, v in groups_by_stage.items()}
+
+    return AnalyticsSnapshot(
+        ok=True,
+        reason="ok",
+        schema_version=ANALYTICS_SCHEMA_VERSION,
+        remote=scope_remote,
+        org=scope_org,
+        repo=scope_repo,
+        total_events=len(parsed_events),
+        overall_summary=overall_summary,
+        by_project=by_project,
+        by_role=by_role,
+        by_model=by_model,
+        by_work_item=by_work_item,
+        by_stage=by_stage,
+        events=tuple(parsed_events),
+    )
+
+
+def snapshot_to_dict(snapshot: AnalyticsSnapshot) -> dict[str, Any]:
+    return snapshot.to_dict()

webui/analytics_views.py

@@ -0,0 +1,248 @@
+"""HTML views for the Model Usage & Performance Analytics console (#651)."""
+
+from __future__ import annotations
+
+import html
+
+from webui.analytics_loader import AnalyticsSnapshot, GroupMetrics, UsageEvent
+from webui.layout import render_page
+
+
+def _escape(text: object) -> str:
+    """HTML-escape dynamic analytics fields (mirrors audit_views / project_views)."""
+    return html.escape(str(text), quote=True)
+
+
+def _render_badge(text: str, badge_type: str = "muted") -> str:
+    return f'<span class="badge badge-{_escape(badge_type)}">{_escape(text)}</span>'
+
+
+def _render_group_table(title: str, groups: dict[str, GroupMetrics], key_header: str = "Group") -> str:
+    if not groups:
+        return (
+            f"<h3>{_escape(title)}</h3>"
+            '<div class="card"><p class="muted">No telemetry events recorded for this dimension.</p></div>'
+        )
+
+    rows = []
+    for key, g in sorted(groups.items(), key=lambda x: x[1].total_events, reverse=True):
+        cost_cell = (
+            f'<span class="accent">{_escape(g.display_cost)}</span>'
+            if g.events_with_cost > 0
+            else _render_badge("Unknown")
+        )
+        tokens_cell = (
+            _escape(g.display_tokens)
+            if g.events_with_tokens > 0
+            else _render_badge("Unknown")
+        )
+        lat_p50 = (
+            _escape(g.display_latency_p50)
+            if g.events_with_latency > 0
+            else _render_badge("Unknown")
+        )
+        lat_p90 = (
+            _escape(g.display_latency_p90)
+            if g.events_with_latency > 0
+            else _render_badge("Unknown")
+        )
+        dur_avg = (
+            _escape(g.display_duration_avg)
+            if g.events_with_duration > 0
+            else _render_badge("Unknown")
+        )
+
+        rows.append(
+            "<tr>"
+            f"<td><strong>{_escape(key)}</strong></td>"
+            f"<td>{g.total_events}</td>"
+            f"<td>{tokens_cell}</td>"
+            f"<td>{cost_cell}</td>"
+            f"<td>{lat_p50}</td>"
+            f"<td>{lat_p90}</td>"
+            f"<td>{dur_avg}</td>"
+            "</tr>"
+        )
+
+    rows_html = "".join(rows)
+    return f"""
+    <h3>{_escape(title)}</h3>
+    <div class="card" style="overflow-x: auto;">
+      <table class="data-table">
+        <thead>
+          <tr>
+            <th>{_escape(key_header)}</th>
+            <th>Events</th>
+            <th>Total Tokens</th>
+            <th>Est. Cost</th>
+            <th>Latency (p50)</th>
+            <th>Latency (p90)</th>
+            <th>Avg Stage Duration</th>
+          </tr>
+        </thead>
+        <tbody>
+          {rows_html}
+        </tbody>
+      </table>
+    </div>
+    """
+
+
+def _render_events_table(events: tuple[UsageEvent, ...]) -> str:
+    if not events:
+        return (
+            "<h3>Recent Usage & Instrumentation Events</h3>"
+            '<div class="card"><p class="muted">No individual telemetry events recorded yet. Opt-in instrumentation via session logging or authorized POST /api/v1/analytics/usage.</p></div>'
+        )
+
+    rows = []
+    for e in list(events)[-50:]:  # Display latest 50
+        if e.issue_number is not None:
+            work_item = f"issue #{e.issue_number}"
+        elif e.pr_number is not None:
+            work_item = f"pr #{e.pr_number}"
+        else:
+            work_item = "unlinked"
+        tokens = (
+            _escape(f"{e.total_tokens:,}")
+            if e.total_tokens is not None
+            else _render_badge("Unknown")
+        )
+        cost = (
+            _escape(f"${e.estimated_cost_usd:.4f}")
+            if e.estimated_cost_usd is not None
+            else _render_badge("Unknown")
+        )
+        latency = (
+            _escape(f"{e.latency_ms} ms")
+            if e.latency_ms is not None
+            else _render_badge("Unknown")
+        )
+        duration = (
+            _escape(f"{e.duration_ms} ms")
+            if e.duration_ms is not None
+            else _render_badge("Unknown")
+        )
+        status_badge = _render_badge(
+            e.status, "success" if e.status == "success" else "danger"
+        )
+
+        rows.append(
+            "<tr>"
+            f"<td>#{e.usage_id}</td>"
+            f"<td><small>{_escape(e.created_at)}</small></td>"
+            f"<td><span class=\"badge\">{_escape(e.role)}</span></td>"
+            f"<td><strong>{_escape(e.model)}</strong></td>"
+            f"<td>{_escape(e.stage)}</td>"
+            f"<td>{_escape(work_item)}</td>"
+            f"<td>{tokens}</td>"
+            f"<td>{cost}</td>"
+            f"<td>{latency}</td>"
+            f"<td>{duration}</td>"
+            f"<td>{status_badge}</td>"
+            "</tr>"
+        )
+
+    rows_html = "".join(rows)
+    return f"""
+    <h3>Recent Telemetry Events</h3>
+    <div class="card" style="overflow-x: auto;">
+      <table class="data-table">
+        <thead>
+          <tr>
+            <th>ID</th>
+            <th>Timestamp</th>
+            <th>Role</th>
+            <th>Model</th>
+            <th>Stage</th>
+            <th>Work Item</th>
+            <th>Tokens</th>
+            <th>Cost</th>
+            <th>Latency</th>
+            <th>Duration</th>
+            <th>Status</th>
+          </tr>
+        </thead>
+        <tbody>
+          {rows_html}
+        </tbody>
+      </table>
+    </div>
+    """
+
+
+def render_analytics_page(snapshot: AnalyticsSnapshot) -> str:
+    """Render the main Model Usage & Performance Analytics console page."""
+    summary = snapshot.overall_summary
+
+    kpi_tokens = (
+        _escape(summary.display_tokens)
+        if summary.events_with_tokens > 0
+        else _render_badge("Unknown")
+    )
+    kpi_cost = (
+        _escape(summary.display_cost)
+        if summary.events_with_cost > 0
+        else _render_badge("Unknown")
+    )
+    kpi_lat_p50 = (
+        _escape(summary.display_latency_p50)
+        if summary.events_with_latency > 0
+        else _render_badge("Unknown")
+    )
+    kpi_dur_avg = (
+        _escape(summary.display_duration_avg)
+        if summary.events_with_duration > 0
+        else _render_badge("Unknown")
+    )
+
+    status_notice = ""
+    if not snapshot.ok:
+        status_notice = (
+            f'<div class="card warning-card"><strong>Degraded Data Source:</strong> '
+            f'{_escape(snapshot.reason)}</div>'
+        )
+
+    body_html = f"""
+    <h2>Model Usage & Performance Analytics (Phase 4)</h2>
+    <p class="muted">
+      Durable console analytics for model usage, token cost, latency percentiles, and workflow-stage performance correlated to issues, PRs, and worker roles.
+    </p>
+
+    {status_notice}
+
+    <div class="notice-card" style="background: rgba(91, 159, 212, 0.1); border: 1px solid var(--border); padding: 0.75rem 1rem; border-radius: 6px; margin-bottom: 1.5rem;">
+      <small><strong>Note on telemetry fidelity:</strong> Missing data or untracked metrics are explicitly labeled as <em>Unknown</em>. No token costs or latency metrics are zero-fabricated.</small>
+    </div>
+
+    <div class="card-grid" style="display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 1rem; margin-bottom: 1.5rem;">
+      <div class="card">
+        <span class="muted" style="font-size: 0.85rem;">Total Events</span>
+        <h3 style="margin: 0.25rem 0 0 0;">{summary.total_events}</h3>
+      </div>
+      <div class="card">
+        <span class="muted" style="font-size: 0.85rem;">Total Tokens</span>
+        <h3 style="margin: 0.25rem 0 0 0;">{kpi_tokens}</h3>
+      </div>
+      <div class="card">
+        <span class="muted" style="font-size: 0.85rem;">Est. Token Cost</span>
+        <h3 style="margin: 0.25rem 0 0 0;">{kpi_cost}</h3>
+      </div>
+      <div class="card">
+        <span class="muted" style="font-size: 0.85rem;">Latency (p50)</span>
+        <h3 style="margin: 0.25rem 0 0 0;">{kpi_lat_p50}</h3>
+      </div>
+      <div class="card">
+        <span class="muted" style="font-size: 0.85rem;">Avg Stage Duration</span>
+        <h3 style="margin: 0.25rem 0 0 0;">{kpi_dur_avg}</h3>
+      </div>
+    </div>
+
+    {_render_group_table("Usage & Cost by Model", snapshot.by_model, "Model")}
+    {_render_group_table("Performance by Workflow Stage", snapshot.by_stage, "Stage")}
+    {_render_group_table("Usage & Cost by Role", snapshot.by_role, "Role")}
+    {_render_group_table("Work Item Analytics", snapshot.by_work_item, "Work Item")}
+    {_render_events_table(snapshot.events)}
+    """
+
+    return render_page(title="Model Usage & Performance Analytics", body_html=body_html)

webui/app.py

@@ -47,6 +47,12 @@ 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.analytics_loader import (
+    load_analytics,
+    record_usage,
+    snapshot_to_dict as analytics_snapshot_to_dict,
+)
+from webui.analytics_views import render_analytics_page
 from webui.system_health import (
     API_PATH as SYSTEM_HEALTH_API_PATH,
     load_system_health,
@@ -567,6 +573,114 @@ async def api_v1_timeline(request: Request) -> JSONResponse:
     return JSONResponse(timeline_snapshot_to_dict(snapshot), status_code=status_code)
 
 
+async def analytics(request: Request) -> HTMLResponse:
+    """Read-only model usage, token cost, latency, and performance analytics HTML view (#651)."""
+    snapshot = load_analytics(
+        remote=request.query_params.get("remote"),
+        org=request.query_params.get("org"),
+        repo=request.query_params.get("repo"),
+        role=request.query_params.get("role"),
+        model=request.query_params.get("model"),
+        stage=request.query_params.get("stage"),
+        issue_number=_query_int(request, "issue"),
+        pr_number=_query_int(request, "pr"),
+        limit=_query_int(request, "limit") or 200,
+    )
+    return HTMLResponse(render_analytics_page(snapshot))
+
+
+async def api_v1_analytics(request: Request) -> JSONResponse:
+    """Read-only model usage, token cost, latency, and performance analytics API (#651)."""
+    snapshot = load_analytics(
+        remote=request.query_params.get("remote"),
+        org=request.query_params.get("org"),
+        repo=request.query_params.get("repo"),
+        role=request.query_params.get("role"),
+        model=request.query_params.get("model"),
+        stage=request.query_params.get("stage"),
+        issue_number=_query_int(request, "issue"),
+        pr_number=_query_int(request, "pr"),
+        limit=_query_int(request, "limit") or 500,
+    )
+    status_code = 200 if snapshot.ok else 500
+    return JSONResponse(analytics_snapshot_to_dict(snapshot), status_code=status_code)
+
+
+async def api_v1_analytics_ingest(request: Request) -> JSONResponse:
+    """Optional session instrumentation ingestion endpoint (#651).
+
+    Fail-closed write: every request is authorized through console_authz
+    (``record_analytics_usage``) before any control-plane DB mutation. Phase 1
+    keeps ``execution_enabled=False`` and denies unauthenticated callers, so
+    this route cannot be used as an unauthenticated write or XSS injection
+    vector (PR #876 F2).
+    """
+    try:
+        body = await request.json()
+    except Exception:
+        body = {}
+    if not isinstance(body, dict):
+        body = {}
+
+    principal = resolve_principal(headers=dict(request.headers))
+    decision = authorize(
+        "record_analytics_usage", principal, for_execution=True
+    )
+    allowed = bool(decision.allowed and decision.execution_enabled)
+    console_audit.record_event(
+        action_id="record_analytics_usage",
+        result=(
+            console_audit.RESULT_ALLOWED
+            if allowed
+            else console_audit.RESULT_DENIED
+        ),
+        decision=decision,
+        principal=principal,
+        target=_audit_target("record_analytics_usage", body),
+        request_id=_request_id(),
+        detail=decision.detail,
+    )
+    authorization = decision.to_dict()
+    if not allowed:
+        return JSONResponse(
+            {
+                "ok": False,
+                "error": "unauthorized",
+                "detail": (
+                    "POST /api/v1/analytics/usage requires an authenticated "
+                    "principal with record_analytics_usage execution enabled"
+                ),
+                "authorization": authorization,
+            },
+            status_code=403,
+        )
+
+    usage_id = record_usage(
+        session_id=body.get("session_id"),
+        remote=body.get("remote", "dadeschools"),
+        org=body.get("org", ""),
+        repo=body.get("repo", ""),
+        project_id=body.get("project_id"),
+        role=body.get("role", "unknown"),
+        model=body.get("model", "unknown"),
+        issue_number=body.get("issue_number") or body.get("issue"),
+        pr_number=body.get("pr_number") or body.get("pr"),
+        stage=body.get("stage", "unknown"),
+        input_tokens=body.get("input_tokens"),
+        output_tokens=body.get("output_tokens"),
+        total_tokens=body.get("total_tokens"),
+        estimated_cost_usd=body.get("estimated_cost_usd"),
+        latency_ms=body.get("latency_ms"),
+        duration_ms=body.get("duration_ms"),
+        status=body.get("status", "success"),
+        metadata=body.get("metadata"),
+    )
+    return JSONResponse(
+        {"ok": True, "usage_id": usage_id, "authorization": authorization},
+        status_code=201,
+    )
+
+
 async def method_not_allowed(request: Request, _exc: Exception) -> Response:
     path = request.url.path
     if path in _AUDIT_MUTATION_PATHS and request.method == "POST":
@@ -608,6 +722,10 @@ def create_app(*, bind_host: str | None = None) -> Starlette:
             Route("/runtime", runtime, methods=["GET"]),
             Route("/api/runtime", api_runtime, methods=["GET"]),
             Route("/api/v1/timeline", api_v1_timeline, methods=["GET"]),
+            Route("/analytics", analytics, methods=["GET"]),
+            Route("/api/analytics", api_v1_analytics, methods=["GET"]),
+            Route("/api/v1/analytics", api_v1_analytics, methods=["GET"]),
+            Route("/api/v1/analytics/usage", api_v1_analytics_ingest, methods=["POST"]),
             Route("/audit", audit, methods=["GET", "POST"]),
             Route("/api/audit", api_audit, methods=["GET", "POST"]),
             Route("/worktrees", worktrees, methods=["GET"]),

webui/console_authz.py

@@ -236,6 +236,19 @@ _ACTION_SPECS: tuple[ConsoleAction, ...] = (
         phase=3,
         summary="Remove a remote feature branch.",
     ),
+    # #651 analytics ingest: local control-plane write, not a Gitea mutation.
+    # Phase 2 gated write so Phase 1 (ACTIVE_PHASE=1) fails closed on execution.
+    ConsoleAction(
+        action_id="record_analytics_usage",
+        task_key="record_analytics_usage",
+        action_class=CLASS_WRITE,
+        minimum_role=OPERATOR,
+        requires_confirmation=True,
+        dual_control=False,
+        break_glass=False,
+        phase=2,
+        summary="Ingest a model-usage / latency analytics event into the control-plane DB.",
+    ),
     # #642: sanctioned daemon lifecycle. These exist so operators have an
     # audited path off `pkill -f mcp_server.py` (#630). Restart drops every
     # in-flight request on a namespace, so it carries the same dual-control and

webui/nav.py

@@ -65,6 +65,7 @@ NAV_GROUPS: tuple[NavGroup, ...] = (
     )),
     NavGroup("Insights", (
         NavItem("/insights", "Insights", "stub"),
+        NavItem("/analytics", "Analytics"),
         NavItem("/audit", "Audit"),
     )),
 )