gitea_mcp_server.py

@@ -195,6 +195,12 @@ RECONCILER_WORKTREE_ENV = "GITEA_RECONCILER_WORKTREE"
 
 import namespace_workspace_binding as nwb  # noqa: E402
 import mcp_namespace_health  # noqa: E402
+import stale_binding_recovery  # noqa: E402
+
+# Worktree env bindings inherited from the parent environment at daemon boot
+# (#702). A value that still equals its boot snapshot was never established by
+# a sanctioned tool in this daemon's lifetime.
+_BOOT_ENV_WORKTREE_BINDINGS = stale_binding_recovery.snapshot_boot_bindings()
 
 
 def _preflight_in_test_mode() -> bool:
@@ -260,8 +266,124 @@ def _actual_profile_role() -> str:
     )
 
 
+def _assess_stale_active_binding(auto_recover: bool = False) -> dict:
+    """Classify the GITEA_ACTIVE_WORKTREE binding; recover when provably stale (#702).
+
+    Runs during ``gitea_resolve_task_capability`` / runtime context. Clearing
+    is the sanctioned in-daemon mechanism and happens only for the two
+    provably-stale classes (missing path, superseded by a sanctioned session
+    lease); an uncorroborated boot-inherited binding is surfaced with the
+    managed-reconnect next action, never cleared silently.
+    """
+    active_value = (os.environ.get(ACTIVE_WORKTREE_ENV) or "").strip() or None
+    try:
+        role = _actual_profile_role()
+    except Exception:
+        role = "author"
+    role_env_key = nwb.ROLE_WORKTREE_ENVS.get(role, AUTHOR_WORKTREE_ENV)
+    boot_value = (
+        (_BOOT_ENV_WORKTREE_BINDINGS.get("active_worktree") or "").strip() or None
+    )
+    classification = stale_binding_recovery.classify_active_worktree_binding(
+        active_value=active_value,
+        role_env_value=(os.environ.get(role_env_key) or "").strip() or None,
+        session_lease_worktree=_reviewer_session_worktree(),
+        boot_inherited=bool(active_value and boot_value == active_value),
+        path_exists=os.path.isdir(active_value) if active_value else None,
+        role_kind=role,
+    )
+    plan = stale_binding_recovery.plan_recovery(classification)
+    applied: dict = {"performed": False}
+    recovery_enabled = (
+        not _preflight_in_test_mode()
+        or os.environ.get("GITEA_FORCE_STALE_BINDING_RECOVERY") == "1"
+    )
+    audit_persisted: bool | None = None
+    if auto_recover and plan.get("clear_allowed") and recovery_enabled:
+        # #702 F6: the durable audit record must exist BEFORE the environment
+        # is cleared. If audit persistence fails the recovery does not run —
+        # an env clear without durable proof is an unauditable mutation.
+        pending_value = (os.environ.get(ACTIVE_WORKTREE_ENV) or "").strip() or None
+        audit_error: str | None = None
+        try:
+            import mcp_session_state as mss
+
+            mss.save_state(
+                kind=mss.KIND_STALE_BINDING_RECOVERY,
+                payload={
+                    "cleared_env": ACTIVE_WORKTREE_ENV,
+                    "cleared_value": pending_value,
+                    "classification": plan.get("classification"),
+                    "reasons": list(plan.get("reasons") or []),
+                    "recovery_status": "pending",
+                },
+            )
+            audit_persisted = True
+        except Exception as exc:
+            audit_persisted = False
+            audit_error = f"{type(exc).__name__}: {exc}"
+        if audit_persisted:
+            applied = stale_binding_recovery.apply_recovery(plan)
+            if applied.get("performed"):
+                try:
+                    import mcp_session_state as mss
+
+                    mss.save_state(
+                        kind=mss.KIND_STALE_BINDING_RECOVERY,
+                        payload={
+                            "cleared_env": applied.get("cleared_env"),
+                            "cleared_value": applied.get("cleared_value"),
+                            "classification": applied.get("classification"),
+                            "reasons": applied.get("reasons"),
+                            "recovery_status": "performed",
+                        },
+                    )
+                except Exception:
+                    # The pre-clear "pending" record is already durable; the
+                    # status refresh is best-effort and never rolls back.
+                    pass
+        else:
+            applied = {
+                "performed": False,
+                "action": stale_binding_recovery.RECOVERY_ACTION_NONE,
+                "audit_write_failed": True,
+                "reasons": [
+                    "audit persistence failed; stale binding NOT cleared "
+                    "(fail closed, #702 F6)"
+                ]
+                + ([audit_error] if audit_error else []),
+            }
+    report = {
+        "classification": classification.get("classification"),
+        "active_worktree": classification.get("active_worktree"),
+        "boot_inherited": classification.get("boot_inherited", False),
+        "clear_eligible": bool(classification.get("clear_eligible")),
+        "recovery_action": plan.get("action"),
+        "recovery_performed": bool(applied.get("performed")),
+        "reasons": classification.get("reasons") or [],
+    }
+    if audit_persisted is not None:
+        report["audit_persisted"] = audit_persisted
+    if applied.get("audit_write_failed"):
+        report["audit_write_failed"] = True
+        report["reasons"] = list(report["reasons"]) + list(
+            applied.get("reasons") or []
+        )
+    if applied.get("performed"):
+        report["cleared_value"] = applied.get("cleared_value")
+    if plan.get("exact_next_action"):
+        report["exact_next_action"] = plan.get("exact_next_action")
+    return report
+
+
 def _resolve_preflight_workspace_path(worktree_path: str | None = None) -> str:
-    """Resolve the namespace-scoped workspace root inspected by pre-flight guards."""
+    """Resolve the namespace-scoped workspace root inspected by pre-flight guards.
+
+    #702 F2: preflight resolves with the same existence verification as the
+    canonical mutation context (verify_paths). A dead env binding must demote
+    here exactly as it does in :func:`_resolve_namespace_mutation_context`,
+    or preflight would inspect a path the mutation guard never uses.
+    """
     role = _effective_workspace_role()
     workspace, _source = nwb.resolve_namespace_workspace(
         role_kind=role,
@@ -271,6 +393,7 @@ def _resolve_preflight_workspace_path(worktree_path: str | None = None) -> str:
             _reviewer_session_worktree() if role in {"reviewer", "merger"} else None
         ),
         profile_name=get_profile().get("profile_name"),
+        verify_paths=True,
     )
     return workspace
 
@@ -317,6 +440,15 @@ def _get_git_root(path: str) -> str | None:
     return (res.stdout or "").strip() or None
 
 
+# #702 F2: synthetic tracked-dirty porcelain returned when the preflight
+# workspace cannot be inspected (missing path, git failure). Shaped as a
+# modified tracked entry so every consumer treats "workspace unavailable"
+# as dirty — an uninspectable workspace must never read as clean.
+PREFLIGHT_WORKSPACE_UNAVAILABLE_PORCELAIN = (
+    " M __gitea_preflight_workspace_unavailable__\n"
+)
+
+
 def _get_workspace_porcelain(worktree_path: str | None = None) -> str:
     """Return tracked-workspace porcelain for pre-flight attribution."""
     if os.environ.get("GITEA_TEST_FORCE_DIRTY"):
@@ -325,6 +457,8 @@ def _get_workspace_porcelain(worktree_path: str | None = None) -> str:
     if override is not None:
         return override
     workspace = _resolve_preflight_workspace_path(worktree_path)
+    if not os.path.isdir(workspace):
+        return PREFLIGHT_WORKSPACE_UNAVAILABLE_PORCELAIN
     try:
         res = subprocess.run(
             ["git", "status", "--porcelain"],
@@ -332,9 +466,11 @@ def _get_workspace_porcelain(worktree_path: str | None = None) -> str:
             text=True,
             cwd=workspace,
         )
-        return res.stdout or ""
     except Exception:
-        return ""
+        return PREFLIGHT_WORKSPACE_UNAVAILABLE_PORCELAIN
+    if res.returncode != 0:
+        return PREFLIGHT_WORKSPACE_UNAVAILABLE_PORCELAIN
+    return res.stdout or ""
 
 
 def _parse_porcelain_entries(porcelain: str) -> dict[str, str]:
@@ -8052,6 +8188,16 @@ def gitea_diagnose_reviewer_pr_lease_handoff(
             except Exception:
                 worktree_clean = None
 
+    # #702: derive owner-process evidence from the durable session-lease
+    # shadow left behind by a crashed daemon. Only a provably dead recorded
+    # owner pid yields False; PID liveness alone never proves ownership.
+    orphan_evidence = reviewer_pr_lease.assess_crashed_session_lease_orphan(
+        reviewer_pr_lease.load_session_lease_shadow(
+            session_id=(active or {}).get("session_id")
+        ),
+        lease=active,
+    )
+
     diagnosis = reviewer_pr_lease.diagnose_reviewer_pr_lease_handoff(
         comments,
         pr_number=pr_number,
@@ -8065,8 +8211,9 @@ def gitea_diagnose_reviewer_pr_lease_handoff(
         formal_reviews=formal_reviews,
         worktree_exists=worktree_exists,
         worktree_clean=worktree_clean,
-        owner_process_alive=None,  # PID never proves ownership; leave unset
+        owner_process_alive=orphan_evidence.get("owner_process_alive"),
     )
+    diagnosis["crashed_session_lease_evidence"] = orphan_evidence
     diagnosis["success"] = True
     diagnosis["remote"] = remote
     diagnosis["authenticated_user"] = username
@@ -8296,6 +8443,15 @@ def gitea_cleanup_obsolete_reviewer_comment_lease(
                 worktree_clean = None
 
     session = reviewer_pr_lease.get_session_lease() or {}
+    # #702: when the caller supplies no owner evidence, consult the durable
+    # session-lease shadow; an explicitly passed value always wins.
+    if owner_process_alive is None:
+        owner_process_alive = reviewer_pr_lease.assess_crashed_session_lease_orphan(
+            reviewer_pr_lease.load_session_lease_shadow(
+                session_id=(lease or {}).get("session_id")
+            ),
+            lease=lease,
+        ).get("owner_process_alive")
     assessment = reviewer_pr_lease.assess_obsolete_reviewer_comment_lease_cleanup(
         comments,
         pr_number=pr_number,
@@ -10145,6 +10301,17 @@ def gitea_get_runtime_context(
             PROJECT_ROOT),
     }
 
+    # #702: read-only visibility into the inherited GITEA_ACTIVE_WORKTREE
+    # binding; recovery itself runs during capability resolution.
+    try:
+        stale_binding = _assess_stale_active_binding(auto_recover=False)
+        if stale_binding.get("classification") != (
+            stale_binding_recovery.CLASSIFICATION_UNBOUND
+        ):
+            result["stale_binding_recovery"] = stale_binding
+    except Exception:
+        pass
+
     parity = _current_master_parity()
     result["master_parity"] = {
         "in_parity": parity["in_parity"],
@@ -11578,6 +11745,18 @@ def gitea_resolve_task_capability(
                 "exact_safe_next_action": next_safe_action,
             }
 
+    # #702 F1: validate (and, when provably stale, recover) the inherited
+    # GITEA_ACTIVE_WORKTREE binding BEFORE the terminal launcher probe. The
+    # probe uses that binding as its cwd; a worktree removed mid-session
+    # would otherwise wedge every mutation-task resolution on 'missing cwd'
+    # before the sanctioned recovery could ever run. Recovery stays
+    # fail-closed: only the provably-stale classes clear, with the durable
+    # audit record persisted first (F6).
+    try:
+        stale_binding = _assess_stale_active_binding(auto_recover=True)
+    except Exception:
+        stale_binding = None
+
     # ── Terminal Launcher Preflight Check (#556) ──
     if task in native_mcp_preference.GITEA_MUTATION_TASKS:
         in_test = _preflight_in_test_mode()
@@ -11601,7 +11780,7 @@ def gitea_resolve_task_capability(
                         "Do not attempt git/pytest finalization or unsafe fallbacks. "
                         "Run gitea_diagnose_terminal, emit blocked-diagnose-report, and stop."
                     )
-                    return {
+                    blocked_result = {
                         "requested_task": task,
                         "required_operation_permission": required_permission,
                         "required_role_kind": required_role,
@@ -11621,6 +11800,11 @@ def gitea_resolve_task_capability(
                         "different_mcp_namespace_required": False,
                         "exact_safe_next_action": next_safe_action,
                     }
+                    if stale_binding is not None and stale_binding.get(
+                        "classification"
+                    ) != stale_binding_recovery.CLASSIFICATION_UNBOUND:
+                        blocked_result["stale_binding_recovery"] = stale_binding
+                    return blocked_result
 
     record_preflight_check("capability", required_role, resolved_task=task)
 
@@ -11810,6 +11994,10 @@ def gitea_resolve_task_capability(
         "different_mcp_namespace_required": different_namespace_required,
         "exact_safe_next_action": next_safe_action,
     }
+    if stale_binding is not None and stale_binding.get("classification") != (
+        stale_binding_recovery.CLASSIFICATION_UNBOUND
+    ):
+        result["stale_binding_recovery"] = stale_binding
     if reason_msg:
         result["reason"] = reason_msg
     if task in ("review_pr", "merge_pr"):
@@ -12685,4 +12873,11 @@ if __name__ == "__main__":
     # processes (e.g. review_pr.py) can detect and refuse profile
     # side-channel overrides (#199).
     _export_session_profile_lock()
+    # #702: an auto-reconnected daemon inherits GITEA_ACTIVE_WORKTREE from its
+    # parent environment. Validate it at boot and clear it only when provably
+    # stale (missing path); anything less certain is surfaced, not cleared.
+    try:
+        _assess_stale_active_binding(auto_recover=True)
+    except Exception:
+        pass
     mcp.run(transport="stdio")

mcp_session_state.py

@@ -36,6 +36,25 @@ KIND_REVIEW_DRAFT = "review_draft"
 # other session proofs; a contaminated session fails closed on gated mutations
 # until a reconciler audits and clears it.
 KIND_STABLE_BRANCH_CONTAMINATION = "stable_branch_contamination"
+# Durable shadow of the in-memory reviewer session lease (#702). Written on
+# every sanctioned record/heartbeat and removed on sanctioned clear, so a
+# daemon that dies without teardown leaves provable orphan evidence (owner
+# pid + session id) for the guarded lease-cleanup path. Never a substitute
+# for the in-session lease: mutation gates ignore it.
+KIND_REVIEWER_SESSION_LEASE = "reviewer_session_lease"
+# Durable audit record written whenever the daemon's sanctioned stale-binding
+# recovery clears an inherited GITEA_ACTIVE_WORKTREE binding (#702).
+KIND_STALE_BINDING_RECOVERY = "stale_binding_recovery"
+
+# Kinds that carry recovery-critical crash-orphan evidence (#702). They are
+# exempt from TTL expiry: a crashed daemon can never refresh its own record,
+# so a wall-clock TTL would silently destroy the only owner-exit proof the
+# guarded cleanup path accepts. These records live until a sanctioned clear
+# terminally reconciles them (durable lifecycle), never until a timer fires.
+RECOVERY_CRITICAL_KINDS = frozenset({
+    KIND_REVIEWER_SESSION_LEASE,
+    KIND_STALE_BINDING_RECOVERY,
+})
 
 
 
@@ -86,6 +105,7 @@ def state_key(
     org: str | None = None,
     repo: str | None = None,
     profile_identity: str | None = None,
+    instance_id: str | None = None,
 ) -> str:
     """Build durable filename key.
 
@@ -93,17 +113,20 @@ def state_key(
     so the primary key is kind + profile identity. Remote/org/repo are stored
     inside the payload and validated on load (#559), which lets a later daemon
     process recover state without already knowing the remote argument.
+
+    *instance_id* extends the key for kinds where one-per-profile collides —
+    concurrent same-profile sessions each own their reviewer-lease shadow
+    (#702 F5), keyed by their lease session id so a later heartbeat can never
+    overwrite or misattribute another session's crash evidence.
     """
     # Keep remote/org/repo parameters for API stability / future kinds; they are
     # intentionally not part of the filename for session-scoped proofs.
     _ = (remote, org, repo)
-    return "-".join(
-        _sanitize_segment(part)
-        for part in (
-            kind,
-            profile_identity or "unknown-profile",
-        )
-    )
+    parts = [kind, profile_identity or "unknown-profile"]
+    instance = (instance_id or "").strip()
+    if instance:
+        parts.append(instance)
+    return "-".join(_sanitize_segment(part) for part in parts)
 
 
 def state_file_path(
@@ -114,6 +137,7 @@ def state_file_path(
     repo: str | None = None,
     profile_identity: str | None = None,
     state_dir: str | None = None,
+    instance_id: str | None = None,
 ) -> str:
     root = (state_dir or default_state_dir()).strip()
     name = state_key(
@@ -122,6 +146,7 @@ def state_file_path(
         org=org,
         repo=repo,
         profile_identity=profile_identity,
+        instance_id=instance_id,
     )
     return os.path.join(root, f"{name}.json")
 
@@ -242,10 +267,12 @@ def identity_match_reasons(
         reasons.append("session state missing recorded_at timestamp (fail closed)")
     else:
         age = _now_utc() - recorded_at
+        record_kind = (str(record.get("kind") or "")).strip()
         if age > timedelta(hours=ttl_hours()):
-            reasons.append(
-                f"session state expired after {ttl_hours():g}h (fail closed)"
-            )
+            if record_kind not in RECOVERY_CRITICAL_KINDS:
+                reasons.append(
+                    f"session state expired after {ttl_hours():g}h (fail closed)"
+                )
         if age < timedelta(0):
             reasons.append("session state recorded_at is in the future (fail closed)")
     return reasons
@@ -259,6 +286,7 @@ def load_state(
     repo: str | None = None,
     profile_identity: str | None = None,
     state_dir: str | None = None,
+    instance_id: str | None = None,
 ) -> dict[str, Any] | None:
     """Load durable state payload when identity checks pass."""
     profile = current_profile_identity(profile_identity=profile_identity)
@@ -269,6 +297,7 @@ def load_state(
         repo=repo,
         profile_identity=profile,
         state_dir=state_dir,
+        instance_id=instance_id,
     )
     lock_path = f"{path}.lock"
     with _exclusive_file_lock(lock_path):
@@ -314,6 +343,7 @@ def save_state(
     repo: str | None = None,
     profile_identity: str | None = None,
     state_dir: str | None = None,
+    instance_id: str | None = None,
 ) -> dict[str, Any] | None:
     """Persist or clear durable state for the given session identity key."""
     profile = current_profile_identity(
@@ -335,6 +365,7 @@ def save_state(
         repo=key_repo,
         profile_identity=profile,
         state_dir=root,
+        instance_id=instance_id,
     )
     lock_path = f"{path}.lock"
     with _exclusive_file_lock(lock_path):
@@ -356,6 +387,8 @@ def save_state(
             body["session_profile_lock"] = profile
         body["recorded_at"] = body.get("recorded_at") or now
         body["updated_at"] = now
+        if (instance_id or "").strip():
+            body["instance_id"] = instance_id.strip()
         if key_remote is not None:
             body["remote"] = key_remote
         if key_org is not None:
@@ -387,6 +420,7 @@ def clear_state(
     repo: str | None = None,
     profile_identity: str | None = None,
     state_dir: str | None = None,
+    instance_id: str | None = None,
 ) -> None:
     save_state(
         kind=kind,
@@ -396,4 +430,56 @@ def clear_state(
         repo=repo,
         profile_identity=profile_identity,
         state_dir=state_dir,
+        instance_id=instance_id,
     )
+
+
+def list_states(
+    *,
+    kind: str,
+    profile_identity: str | None = None,
+    state_dir: str | None = None,
+) -> list[dict[str, Any]]:
+    """Enumerate durable records of *kind* across all instance keys.
+
+    Crash recovery cannot know which session id left a shadow behind, so it
+    must be able to enumerate every record of a kind (#702 F5). Identity
+    checks (profile / TTL policy) apply per record exactly as in
+    :func:`load_state`; records that fail closed are omitted.
+    """
+    root = (state_dir or default_state_dir()).strip()
+    if not root or not os.path.isdir(root):
+        return []
+    profile = current_profile_identity(profile_identity=profile_identity)
+    results: list[dict[str, Any]] = []
+    try:
+        names = sorted(os.listdir(root))
+    except OSError:
+        return []
+    for name in names:
+        if not name.endswith(".json") or name.startswith("."):
+            continue
+        envelope = _read_json(os.path.join(root, name))
+        if not envelope or envelope.get("kind") != kind:
+            continue
+        payload = envelope.get("payload")
+        if not isinstance(payload, dict):
+            continue
+        merged = dict(payload)
+        for key in (
+            "kind",
+            "remote",
+            "org",
+            "repo",
+            "profile_identity",
+            "session_profile_lock",
+            "recorded_at",
+            "updated_at",
+            "writer_pid",
+        ):
+            if key in envelope and key not in merged:
+                merged[key] = envelope[key]
+        if identity_match_reasons(merged, profile_identity=profile):
+            continue
+        results.append(merged)
+    return results

namespace_workspace_binding.py

@@ -56,23 +56,46 @@ def resolve_namespace_workspace(
     env: dict[str, str] | os._Environ | None = None,
     session_lease_worktree: str | None = None,
     profile_name: str | None = None,
+    demotions: list[str] | None = None,
+    verify_paths: bool = False,
 ) -> tuple[str, str]:
-    """Return ``(resolved_path, binding_source)`` for *role_kind*."""
+    """Return ``(resolved_path, binding_source)`` for *role_kind*.
+
+    With *verify_paths*, env-sourced candidates whose path no longer exists
+    are demoted (#702): a binding to a deleted worktree can never name a
+    valid task workspace, so resolution falls through to the next candidate.
+    Explicit arguments are never demoted — a caller-declared path must fail
+    loudly downstream rather than silently rebind. Demotion notes are
+    appended to *demotions* when provided. Runtime-context and mutation
+    guards resolve through :func:`resolve_namespace_mutation_context`, which
+    always verifies.
+    """
     env_map = env if env is not None else os.environ
     role = normalize_role_kind(role_kind, profile_name=profile_name)
     role_env_key = ROLE_WORKTREE_ENVS[role]
 
-    for candidate, source in (
-        (worktree_path, "worktree_path argument"),
-        (worktree, "worktree argument"),
-        (_env_value(env_map, ACTIVE_WORKTREE_ENV), f"{ACTIVE_WORKTREE_ENV} environment variable"),
-        (_env_value(env_map, role_env_key), f"{role_env_key} environment variable"),
+    for candidate, source, env_sourced in (
+        (worktree_path, "worktree_path argument", False),
+        (worktree, "worktree argument", False),
+        (_env_value(env_map, ACTIVE_WORKTREE_ENV),
+         f"{ACTIVE_WORKTREE_ENV} environment variable", True),
+        (_env_value(env_map, role_env_key),
+         f"{role_env_key} environment variable", True),
         (session_lease_worktree if role in {"reviewer", "merger"} else None,
-         "reviewer PR lease worktree"),
+         "reviewer PR lease worktree", False),
     ):
         text = (candidate or "").strip()
-        if text:
-            return os.path.realpath(os.path.abspath(text)), source
+        if not text:
+            continue
+        real = os.path.realpath(os.path.abspath(text))
+        if verify_paths and env_sourced and not os.path.isdir(real):
+            if demotions is not None:
+                demotions.append(
+                    f"{source} '{real}' demoted: path no longer exists "
+                    "(stale binding, #702)"
+                )
+            continue
+        return real, source
 
     return os.path.realpath(process_project_root), "MCP server process root (default)"
 
@@ -88,6 +111,7 @@ def resolve_namespace_mutation_context(
     profile_name: str | None = None,
 ) -> dict:
     """Shared workspace resolution for runtime_context and mutation guards."""
+    demotions: list[str] = []
     workspace, binding_source = resolve_namespace_workspace(
         role_kind=role_kind,
         worktree_path=worktree_path,
@@ -96,6 +120,8 @@ def resolve_namespace_mutation_context(
         env=env,
         session_lease_worktree=session_lease_worktree,
         profile_name=profile_name,
+        demotions=demotions,
+        verify_paths=True,
     )
     process_root = os.path.realpath(process_project_root)
     role = normalize_role_kind(role_kind, profile_name=profile_name)
@@ -111,7 +137,7 @@ def resolve_namespace_mutation_context(
         "workspace_path": workspace,
         "workspace_binding_source": binding_source,
         "workspace_role_kind": role,
-        "ignored_bindings": pollution.get("ignored_bindings") or [],
+        "ignored_bindings": demotions + (pollution.get("ignored_bindings") or []),
         "process_project_root": process_root,
         "canonical_repo_root": canonical_root,
         "roots_aligned": canonical_root == process_root,

reviewer_pr_lease.py

@@ -407,18 +407,194 @@ def record_session_lease(
     if lease_provenance:
         stored["lease_provenance"] = dict(lease_provenance)
     _SESSION_LEASE = stored
+    _persist_session_lease_shadow(stored)
     return dict(_SESSION_LEASE)
 
 
 def clear_session_lease() -> None:
     global _SESSION_LEASE
+    prior = _SESSION_LEASE
     _SESSION_LEASE = None
+    _persist_session_lease_shadow(None, prior=prior)
 
 
 def get_session_lease() -> dict[str, Any] | None:
     return dict(_SESSION_LEASE) if _SESSION_LEASE else None
 
 
+def _persist_session_lease_shadow(
+    lease: dict[str, Any] | None,
+    *,
+    prior: dict[str, Any] | None = None,
+) -> None:
+    """Best-effort durable shadow of the in-session lease (#702).
+
+    A daemon that dies without teardown leaves this record behind, giving a
+    later process provable orphan evidence (owner pid + session id) for the
+    guarded cleanup path. Observability only — mutation gates never read it,
+    and failures here must never block lease operations.
+
+    Shadows are keyed by lease session id (#702 F5): concurrent same-profile
+    sessions each own a distinct record, so one session's heartbeat can never
+    overwrite or misattribute another's crash evidence. A sanctioned clear is
+    the terminal reconciliation of that record's lifecycle.
+    """
+    try:
+        import mcp_session_state as mss
+
+        if lease is None:
+            sid = ((prior or {}).get("session_id") or "").strip() or None
+            if sid:
+                mss.clear_state(
+                    kind=mss.KIND_REVIEWER_SESSION_LEASE, instance_id=sid
+                )
+            # Legacy single-slot record from pre-F5 code: clearing it is safe
+            # because collision-safe writes never target that key again.
+            mss.clear_state(kind=mss.KIND_REVIEWER_SESSION_LEASE)
+            return
+        mss.save_state(
+            kind=mss.KIND_REVIEWER_SESSION_LEASE,
+            instance_id=((lease.get("session_id") or "").strip() or None),
+            payload={
+                "pr_number": lease.get("pr_number"),
+                "session_id": lease.get("session_id"),
+                "comment_id": lease.get("comment_id"),
+                "candidate_head": lease.get("candidate_head"),
+                "worktree": lease.get("worktree"),
+                "phase": lease.get("phase"),
+                "reviewer_identity": lease.get("reviewer_identity"),
+                "profile": lease.get("profile"),
+                "lease_repo": lease.get("repo"),
+                "owner_pid": os.getpid(),
+            },
+        )
+    except Exception:
+        pass
+
+
+def load_session_lease_shadow(
+    session_id: str | None = None,
+) -> dict[str, Any] | None:
+    """Load the durable session-lease shadow left by this profile identity.
+
+    With *session_id*, load that session's collision-safe record (#702 F5),
+    falling back to the legacy single-slot record only when its payload names
+    the same session. Without *session_id*, return the legacy record or the
+    sole surviving instance record — ambiguity (multiple candidates) returns
+    ``None`` because a shadow that cannot be attributed proves nothing.
+    """
+    try:
+        import mcp_session_state as mss
+
+        sid = (session_id or "").strip()
+        if sid:
+            record = mss.load_state(
+                kind=mss.KIND_REVIEWER_SESSION_LEASE, instance_id=sid
+            )
+            if record is not None:
+                return record
+            legacy = mss.load_state(kind=mss.KIND_REVIEWER_SESSION_LEASE)
+            if legacy and (legacy.get("session_id") or "").strip() == sid:
+                return legacy
+            return None
+        legacy = mss.load_state(kind=mss.KIND_REVIEWER_SESSION_LEASE)
+        if legacy is not None:
+            return legacy
+        records = mss.list_states(kind=mss.KIND_REVIEWER_SESSION_LEASE)
+        if len(records) == 1:
+            return records[0]
+        return None
+    except Exception:
+        return None
+
+
+def _pid_alive(pid: int) -> bool:
+    """Probe process existence; fail closed toward 'alive' when unsure."""
+    try:
+        os.kill(int(pid), 0)
+        return True
+    except ProcessLookupError:
+        return False
+    except PermissionError:
+        return True
+    except Exception:
+        return True
+
+
+def assess_crashed_session_lease_orphan(
+    shadow: dict[str, Any] | None,
+    *,
+    lease: dict[str, Any] | None,
+    current_pid: int | None = None,
+    pid_alive: bool | None = None,
+) -> dict[str, Any]:
+    """Derive owner-process evidence for a durable lease from the shadow (#702).
+
+    Returns ``owner_process_alive`` tri-state. Only a provably dead recorded
+    owner pid yields ``False`` (a dead pid cannot still be running the owning
+    daemon); an alive pid is *not* ownership proof and stays ``None`` unless
+    it is this very process. Session ids must match exactly — the shadow of a
+    different lease proves nothing.
+    """
+    reasons: list[str] = []
+    if not shadow or not lease:
+        return {
+            "orphan_evidence": False,
+            "owner_process_alive": None,
+            "reasons": ["no durable session-lease shadow evidence available"],
+        }
+    shadow_sid = (shadow.get("session_id") or "").strip()
+    lease_sid = (lease.get("session_id") or "").strip()
+    if not shadow_sid or not lease_sid or shadow_sid != lease_sid:
+        return {
+            "orphan_evidence": False,
+            "owner_process_alive": None,
+            "reasons": [
+                "session-lease shadow session_id does not match the durable "
+                f"lease (shadow={shadow_sid or None}, lease={lease_sid or None})"
+            ],
+        }
+    owner_pid = shadow.get("owner_pid") or shadow.get("writer_pid")
+    try:
+        owner_pid = int(owner_pid)
+    except (TypeError, ValueError):
+        return {
+            "orphan_evidence": False,
+            "owner_process_alive": None,
+            "reasons": ["session-lease shadow has no usable owner pid (fail closed)"],
+        }
+    this_pid = current_pid if current_pid is not None else os.getpid()
+    if owner_pid == this_pid:
+        return {
+            "orphan_evidence": False,
+            "owner_process_alive": True,
+            "owner_pid": owner_pid,
+            "reasons": ["shadow owner pid is the current process"],
+        }
+    alive = pid_alive if pid_alive is not None else _pid_alive(owner_pid)
+    if alive:
+        reasons.append(
+            f"shadow owner pid {owner_pid} observed alive; PID liveness is not "
+            "ownership proof — owner evidence stays unknown (fail closed)"
+        )
+        return {
+            "orphan_evidence": False,
+            "owner_process_alive": None,
+            "owner_pid": owner_pid,
+            "reasons": reasons,
+        }
+    reasons.append(
+        f"shadow owner pid {owner_pid} is dead: the daemon that recorded the "
+        "matching session lease exited without teardown (crash orphan, #702)"
+    )
+    return {
+        "orphan_evidence": True,
+        "owner_process_alive": False,
+        "owner_pid": owner_pid,
+        "reasons": reasons,
+    }
+
+
 def assess_mutation_lease_gate(
     *,
     pr_number: int,
@@ -557,6 +733,7 @@ _HANDOFF_CLASSIFICATIONS = frozenset({
     "foreign_completed_superseded_head",
     "foreign_expired_superseded_head",
     "orphaned_owner_missing",
+    "orphaned_expired_superseded_head",
     "ambiguous_conflicting_evidence",
     "instructed_lease_missing_with_replacement",
     "worktree_binding_mismatch",
@@ -850,6 +1027,38 @@ def assess_obsolete_reviewer_comment_lease_cleanup(
             classification = "foreign_expired_superseded_head"
         elif head_superseded and has_terminal and not past_expiry:
             classification = "foreign_completed_superseded_head"
+        elif head_superseded and not has_terminal and past_expiry:
+            # Crash-orphan shape (#702): the lease outlived its head with no
+            # formal terminal review and has now passed canonical expiry, so
+            # it no longer gates fresh acquisition. Guarded cleanup of the
+            # ledger marker still demands provable owner-process-exit
+            # evidence and a safe worktree — never inferred.
+            classification = "orphaned_expired_superseded_head"
+            if owner_process_alive is True:
+                fail_closed_reasons.append(
+                    "lease past expiry on superseded head but owner process "
+                    "still alive; cleanup denied"
+                )
+            elif owner_process_alive is None:
+                fail_closed_reasons.append(
+                    "expired superseded-head lease with no terminal review: "
+                    "cleanup requires provable owner-process-exit evidence "
+                    "(owner_process_alive=false); the expired lease no longer "
+                    "gates fresh acquisition"
+                )
+            elif worktree_clean is False:
+                fail_closed_reasons.append(
+                    "owner process absent but worktree dirty; cleanup denied"
+                )
+            elif not (worktree_clean is True or worktree_exists is False):
+                # #702 F3: unknown worktree evidence must fail closed, exactly
+                # like the sibling orphaned_owner_missing gate and the
+                # diagnosis path — cleanup needs affirmative safe evidence.
+                fail_closed_reasons.append(
+                    "owner process absent but worktree evidence is unknown; "
+                    "cleanup requires affirmative safe evidence "
+                    "(worktree_clean=true or worktree_exists=false)"
+                )
         elif head_superseded and not has_terminal:
             classification = "ambiguous_conflicting_evidence"
             fail_closed_reasons.append(
@@ -891,6 +1100,7 @@ def assess_obsolete_reviewer_comment_lease_cleanup(
                 "foreign_expired_superseded_head",
                 "foreign_expired_current_head",
                 "orphaned_owner_missing",
+                "orphaned_expired_superseded_head",
             }:
                 fail_closed_reasons.append(
                     "controller/recovery capability required "
@@ -909,6 +1119,7 @@ def assess_obsolete_reviewer_comment_lease_cleanup(
             "foreign_completed_superseded_head",
             "foreign_expired_superseded_head",
             "orphaned_owner_missing",
+            "orphaned_expired_superseded_head",
             "foreign_expired_current_head",
         }
         # foreign_expired_current_head needs orphan/clean worktree + authority.
@@ -1181,6 +1392,30 @@ def diagnose_reviewer_pr_lease_handoff(
                 "foreign lease pinned to superseded head with completed formal "
                 "review; use guarded obsolete-lease cleanup (do not wait indefinitely)"
             )
+        elif not is_own and head_superseded and not terminal and past_expiry:
+            # Crash-orphan shape after canonical expiry (#702): the expired
+            # marker no longer gates acquisition, so a fresh reviewer may
+            # acquire at the current head. Guarded ledger cleanup becomes
+            # available only with provable owner-exit evidence.
+            classification = "orphaned_expired_superseded_head"
+            if owner_process_alive is False and (
+                worktree_clean is True or worktree_exists is False
+            ):
+                next_action = NEXT_ACTION_CLEANUP_OBSOLETE_LEASE
+                reasons.append(
+                    "expired superseded-head lease with no terminal review and "
+                    "provable owner-process exit (crash orphan, #702); guarded "
+                    "obsolete-lease cleanup eligible"
+                )
+            else:
+                next_action = NEXT_ACTION_ACQUIRE
+                reasons.append(
+                    "lease head superseded and lease past canonical expiry with "
+                    "no formal terminal review (crash orphan, #702); expired "
+                    "marker no longer gates acquisition — acquire a fresh lease "
+                    "at the current head; guarded cleanup needs "
+                    "owner_process_alive=false and a clean/absent worktree"
+                )
         elif not is_own and head_superseded and not terminal:
             classification = "ambiguous_conflicting_evidence"
             next_action = NEXT_ACTION_WAIT

stale_binding_recovery.py

@@ -0,0 +1,257 @@
+"""Sanctioned recovery for stale env-bound task workspace bindings (#702).
+
+When the MCP daemon dies from an unhandled exception it never runs teardown,
+and the auto-reconnected daemon inherits ``GITEA_ACTIVE_WORKTREE`` from its
+parent environment. That inherited value can permanently bind the fresh
+session to a prior task's worktree (the PR #701 / ``review-pr-654`` incident).
+
+This module classifies the active env binding against live session evidence
+and produces a fail-closed recovery plan. Only two situations permit the
+daemon to clear the binding on its own:
+
+- the bound path no longer exists on disk (``provably_stale_missing_path``)
+- the binding was inherited at daemon boot and a *sanctioned* in-session
+  reviewer/merger lease later bound a different worktree
+  (``superseded_by_session_lease``)
+
+Everything else is surfaced (``unverified_inherited``) and left for the
+managed reconnect path — never cleared silently, never rebound to a guessed
+worktree.
+"""
+
+from __future__ import annotations
+
+import os
+from typing import Any
+
+ACTIVE_WORKTREE_ENV = "GITEA_ACTIVE_WORKTREE"
+
+CLASSIFICATION_UNBOUND = "unbound"
+CLASSIFICATION_CORROBORATED = "corroborated"
+CLASSIFICATION_UNVERIFIED_INHERITED = "unverified_inherited"
+CLASSIFICATION_PROVABLY_STALE_MISSING_PATH = "provably_stale_missing_path"
+CLASSIFICATION_SUPERSEDED_BY_SESSION_LEASE = "superseded_by_session_lease"
+
+CLASSIFICATIONS = frozenset({
+    CLASSIFICATION_UNBOUND,
+    CLASSIFICATION_CORROBORATED,
+    CLASSIFICATION_UNVERIFIED_INHERITED,
+    CLASSIFICATION_PROVABLY_STALE_MISSING_PATH,
+    CLASSIFICATION_SUPERSEDED_BY_SESSION_LEASE,
+})
+
+# Roles whose task workspace is owned by a lease lifecycle, so an inherited
+# generic binding without a corroborating lease is suspect.
+LEASE_BOUND_ROLES = frozenset({"reviewer", "merger"})
+
+RECOVERY_ACTION_NONE = "none"
+RECOVERY_ACTION_CLEAR_ENV = "clear_env"
+
+
+def _norm(path: str | None) -> str:
+    text = (path or "").strip()
+    if not text:
+        return ""
+    return os.path.realpath(os.path.abspath(text))
+
+
+def snapshot_boot_bindings(
+    env: dict[str, str] | os._Environ | None = None,
+) -> dict[str, Any]:
+    """Capture worktree env bindings present when the daemon booted.
+
+    A value present in this snapshot was inherited from the parent
+    environment, not established by any sanctioned tool in this daemon's
+    lifetime.
+    """
+    env_map = env if env is not None else os.environ
+    return {
+        "active_worktree": (env_map.get(ACTIVE_WORKTREE_ENV) or "").strip() or None,
+    }
+
+
+def classify_active_worktree_binding(
+    *,
+    active_value: str | None,
+    role_env_value: str | None = None,
+    session_lease_worktree: str | None = None,
+    boot_inherited: bool,
+    path_exists: bool | None,
+    role_kind: str | None = None,
+) -> dict[str, Any]:
+    """Classify the GITEA_ACTIVE_WORKTREE binding against live evidence.
+
+    Fail closed: unknown evidence never yields a clear-eligible class.
+    """
+    reasons: list[str] = []
+    active = _norm(active_value)
+    if not active:
+        return {
+            "classification": CLASSIFICATION_UNBOUND,
+            "clear_eligible": False,
+            "active_worktree": None,
+            "reasons": ["no GITEA_ACTIVE_WORKTREE binding present"],
+        }
+
+    role = (role_kind or "").strip().lower()
+    role_env = _norm(role_env_value)
+    lease_wt = _norm(session_lease_worktree)
+
+    result: dict[str, Any] = {
+        "active_worktree": active,
+        "boot_inherited": bool(boot_inherited),
+        "role_kind": role or None,
+        "session_lease_worktree": lease_wt or None,
+        "role_env_worktree": role_env or None,
+    }
+
+    if path_exists is False:
+        reasons.append(
+            f"bound worktree '{active}' no longer exists on disk; the binding "
+            "cannot name a valid task workspace"
+        )
+        result.update({
+            "classification": CLASSIFICATION_PROVABLY_STALE_MISSING_PATH,
+            "clear_eligible": True,
+            "reasons": reasons,
+        })
+        return result
+
+    if lease_wt and lease_wt == active:
+        reasons.append("binding matches the sanctioned in-session lease worktree")
+        result.update({
+            "classification": CLASSIFICATION_CORROBORATED,
+            "clear_eligible": False,
+            "reasons": reasons,
+        })
+        return result
+
+    if lease_wt and lease_wt != active and boot_inherited:
+        reasons.append(
+            "boot-inherited binding disagrees with the sanctioned in-session "
+            f"lease worktree '{lease_wt}'; the lease is live authority"
+        )
+        result.update({
+            "classification": CLASSIFICATION_SUPERSEDED_BY_SESSION_LEASE,
+            "clear_eligible": True,
+            "reasons": reasons,
+        })
+        return result
+
+    if lease_wt and lease_wt != active and not boot_inherited:
+        # Set after boot by tooling; disagreement is surfaced, never auto-cleared.
+        reasons.append(
+            "post-boot binding disagrees with the in-session lease worktree; "
+            "surfacing only (fail closed, no automatic clear)"
+        )
+        result.update({
+            "classification": CLASSIFICATION_UNVERIFIED_INHERITED,
+            "clear_eligible": False,
+            "reasons": reasons,
+        })
+        return result
+
+    if role_env and role_env == active:
+        reasons.append("binding matches the role-specific worktree env binding")
+        result.update({
+            "classification": CLASSIFICATION_CORROBORATED,
+            "clear_eligible": False,
+            "reasons": reasons,
+        })
+        return result
+
+    if boot_inherited and role in LEASE_BOUND_ROLES and not lease_wt:
+        reasons.append(
+            "binding was inherited at daemon boot, no sanctioned in-session "
+            f"lease corroborates it, and the {role} role binds workspaces "
+            "through the lease lifecycle; treat as unverified until a fresh "
+            "lease or managed reconnect re-establishes the workspace"
+        )
+        result.update({
+            "classification": CLASSIFICATION_UNVERIFIED_INHERITED,
+            "clear_eligible": False,
+            "reasons": reasons,
+        })
+        return result
+
+    reasons.append("no contradicting evidence; binding treated as corroborated")
+    result.update({
+        "classification": CLASSIFICATION_CORROBORATED,
+        "clear_eligible": False,
+        "reasons": reasons,
+    })
+    return result
+
+
+def plan_recovery(classification_result: dict[str, Any]) -> dict[str, Any]:
+    """Turn a classification into an explicit, fail-closed recovery plan."""
+    classification = classification_result.get("classification")
+    clear_eligible = bool(classification_result.get("clear_eligible"))
+    reasons = list(classification_result.get("reasons") or [])
+
+    if classification not in CLASSIFICATIONS:
+        return {
+            "action": RECOVERY_ACTION_NONE,
+            "clear_allowed": False,
+            "classification": classification,
+            "reasons": reasons + ["unknown classification (fail closed)"],
+        }
+
+    if clear_eligible and classification in {
+        CLASSIFICATION_PROVABLY_STALE_MISSING_PATH,
+        CLASSIFICATION_SUPERSEDED_BY_SESSION_LEASE,
+    }:
+        return {
+            "action": RECOVERY_ACTION_CLEAR_ENV,
+            "clear_allowed": True,
+            "classification": classification,
+            "active_worktree": classification_result.get("active_worktree"),
+            "reasons": reasons,
+        }
+
+    exact_next_action = None
+    if classification == CLASSIFICATION_UNVERIFIED_INHERITED:
+        exact_next_action = (
+            "managed recovery required: reconnect the MCP namespace through "
+            "the managed client configuration (or start a fresh session) so "
+            "the daemon boots without the inherited GITEA_ACTIVE_WORKTREE, or "
+            "corroborate the binding by acquiring a lease for that worktree; "
+            "do not clear or rewrite the environment manually"
+        )
+    return {
+        "action": RECOVERY_ACTION_NONE,
+        "clear_allowed": False,
+        "classification": classification,
+        "active_worktree": classification_result.get("active_worktree"),
+        "reasons": reasons,
+        **({"exact_next_action": exact_next_action} if exact_next_action else {}),
+    }
+
+
+def apply_recovery(
+    plan: dict[str, Any],
+    env: dict[str, str] | os._Environ | None = None,
+) -> dict[str, Any]:
+    """Apply a clear-eligible plan by removing the stale env binding.
+
+    This is the sanctioned in-daemon mechanism (#702 AC2); callers must
+    persist the returned record for audit. Refuses anything but an explicit
+    ``clear_env`` plan.
+    """
+    env_map = env if env is not None else os.environ
+    if not plan.get("clear_allowed") or plan.get("action") != RECOVERY_ACTION_CLEAR_ENV:
+        return {
+            "performed": False,
+            "action": RECOVERY_ACTION_NONE,
+            "reasons": ["recovery plan does not authorize clearing (fail closed)"],
+        }
+    cleared_value = (env_map.get(ACTIVE_WORKTREE_ENV) or "").strip() or None
+    env_map.pop(ACTIVE_WORKTREE_ENV, None)
+    return {
+        "performed": True,
+        "action": RECOVERY_ACTION_CLEAR_ENV,
+        "cleared_env": ACTIVE_WORKTREE_ENV,
+        "cleared_value": cleared_value,
+        "classification": plan.get("classification"),
+        "reasons": list(plan.get("reasons") or []),
+    }

tests/test_issue_691_obsolete_reviewer_lease_cleanup.py

@@ -561,12 +561,29 @@ class TestIssue691SupersededHeadCleanup(unittest.TestCase):
         self.assertTrue(any("owns the lease" in r for r in result["reasons"]))
 
     def test_superseded_without_terminal_review_denied(self):
+        # Pre-expiry the missing terminal review is ambiguous (fail closed);
+        # post-expiry with unknown owner evidence it is a crash-orphan (#702)
+        # that still fails closed until owner-process exit is proven.
         now = datetime(2026, 7, 13, 5, 0, 0, tzinfo=timezone.utc)
         expires = datetime(2026, 7, 13, 4, 23, 0, tzinfo=timezone.utc)
         claim = _lease_comment(expires_at=expires, last_activity=expires - timedelta(hours=1))
-        result = _assess([claim], formal_reviews=[], now=now)
+        result = _assess(
+            [claim], formal_reviews=[], now=now, owner_process_alive=None
+        )
         self.assertFalse(result["cleanup_allowed"])
-        self.assertEqual(result["classification"], "ambiguous_conflicting_evidence")
+        self.assertEqual(
+            result["classification"], "orphaned_expired_superseded_head"
+        )
+
+        fresh_expires = now + timedelta(minutes=60)
+        fresh = _lease_comment(
+            expires_at=fresh_expires, last_activity=now - timedelta(minutes=5)
+        )
+        pre_expiry = _assess([fresh], formal_reviews=[], now=now)
+        self.assertFalse(pre_expiry["cleanup_allowed"])
+        self.assertEqual(
+            pre_expiry["classification"], "ambiguous_conflicting_evidence"
+        )
 
 
 class TestIssue691DiagnoseClassifications(unittest.TestCase):

tests/test_issue_702_review_findings_f1_f6.py

@@ -0,0 +1,693 @@
+"""Regression tests for the PR #703 REQUEST_CHANGES findings F1–F6 (#702).
+
+Formal review at head 889931d independently reproduced six defects:
+
+F1 — stale-binding recovery ran only AFTER the terminal launcher probe in
+     ``gitea_resolve_task_capability``; a worktree removed mid-session wedged
+     every mutation-task resolution on 'missing cwd' before recovery.
+F2 — ``_resolve_preflight_workspace_path`` skipped the existence checks the
+     canonical mutation context applies; a dead binding could produce empty
+     porcelain and read as a clean workspace.
+F3 — ``orphaned_expired_superseded_head`` cleanup accepted unknown
+     ``worktree_exists``/``worktree_clean`` evidence.
+F4 — the 4-hour session-state TTL silently discarded recovery-critical
+     crash-orphan shadow evidence.
+F5 — the single same-profile shadow slot let concurrent sessions overwrite
+     each other's crash evidence.
+F6 — the environment was cleared BEFORE the audit record was persisted, and
+     audit-write failure was swallowed.
+"""
+
+from __future__ import annotations
+
+import json
+import os
+import shutil
+import sys
+import tempfile
+import unittest
+from datetime import datetime, timedelta, timezone
+from pathlib import Path
+from unittest.mock import patch
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+import mcp_session_state as mss  # noqa: E402
+import namespace_workspace_binding as nwb  # noqa: E402
+import reviewer_pr_lease as leases  # noqa: E402
+import stale_binding_recovery as sbr  # noqa: E402
+import mcp_server  # noqa: E402
+
+REPO = "Scaled-Tech-Consulting/Gitea-Tools"
+OLD_HEAD = "b" * 40
+NEW_HEAD = "6" * 40
+
+CONFIG = {
+    "version": 2,
+    "contexts": {
+        "ctx": {
+            "enabled": True,
+            "gitea": {"enabled": True, "base_url": "https://gitea.example.com"},
+        }
+    },
+    "profiles": {
+        "prgs-author": {
+            "enabled": True,
+            "context": "ctx",
+            "role": "author",
+            "username": "jcwalker3",
+            "auth": {"type": "env", "name": "GITEA_TOKEN_AUTHOR"},
+            "allowed_operations": [
+                "gitea.read", "gitea.issue.create", "gitea.issue.comment",
+                "gitea.pr.create", "gitea.branch.push",
+            ],
+            "forbidden_operations": [
+                "gitea.pr.approve", "gitea.pr.merge", "gitea.pr.review",
+            ],
+            "execution_profile": "prgs-author",
+        },
+    },
+    "rules": {"allow_runtime_switching": False},
+}
+
+
+def _now() -> datetime:
+    return datetime.now(timezone.utc)
+
+
+class _CapabilityHarness(unittest.TestCase):
+    """Shared config/env plumbing for resolve-capability integration tests."""
+
+    def setUp(self):
+        self._remotes = patch.dict(mcp_server.REMOTES, {
+            "prgs": {
+                "host": "gitea.example.com",
+                "org": "Scaled-Tech-Consulting",
+                "repo": "Gitea-Tools",
+            },
+        })
+        self._remotes.start()
+        mcp_server._IDENTITY_CACHE.clear()
+        self._dir = tempfile.TemporaryDirectory()
+        self.config_path = os.path.join(self._dir.name, "profiles.json")
+        with open(self.config_path, "w", encoding="utf-8") as fh:
+            fh.write(json.dumps(CONFIG))
+
+    def tearDown(self):
+        self._remotes.stop()
+        mcp_server._IDENTITY_CACHE.clear()
+        self._dir.cleanup()
+
+    def _env(self, **extra):
+        env = {
+            "GITEA_MCP_CONFIG": self.config_path,
+            "GITEA_MCP_PROFILE": "prgs-author",
+            "GITEA_TOKEN_AUTHOR": "author-pass",
+        }
+        env.update(extra)
+        return env
+
+    def _deleted_worktree(self) -> str:
+        path = tempfile.mkdtemp(prefix="gitea-removed-worktree-")
+        shutil.rmtree(path)
+        return path
+
+
+class TestF1RecoveryBeforeTerminalProbe(_CapabilityHarness):
+    """F1: recovery must run before the terminal cwd probe can wedge."""
+
+    @patch("mcp_server.api_request", return_value={"login": "jcwalker3"})
+    @patch("mcp_server.get_auth_header", return_value="token author-pass")
+    def test_removed_worktree_recovers_before_probe(self, _auth, _api):
+        missing = self._deleted_worktree()
+        env = self._env(
+            GITEA_ACTIVE_WORKTREE=missing,
+            GITEA_FORCE_TERMINAL_PROBE="1",
+            GITEA_FORCE_STALE_BINDING_RECOVERY="1",
+        )
+        with patch.dict(os.environ, env):
+            res = mcp_server.gitea_resolve_task_capability(
+                task="create_pr", remote="prgs"
+            )
+            # The provably-stale binding was cleared before the probe ran.
+            self.assertNotIn("GITEA_ACTIVE_WORKTREE", os.environ)
+        self.assertFalse(res.get("terminal_launcher_unhealthy"))
+        report = res.get("stale_binding_recovery") or {}
+        self.assertEqual(
+            report.get("classification"),
+            sbr.CLASSIFICATION_PROVABLY_STALE_MISSING_PATH,
+        )
+        self.assertTrue(report.get("recovery_performed"))
+        self.assertTrue(res.get("allowed_in_current_session"))
+
+    @patch("mcp_server.api_request", return_value={"login": "jcwalker3"})
+    @patch("mcp_server.get_auth_header", return_value="token author-pass")
+    def test_probe_block_still_carries_recovery_report(self, _auth, _api):
+        # Recovery disabled (test mode without the force flag) preserves the
+        # fail-closed probe block, but the block must now carry the
+        # classification evidence instead of hiding it.
+        missing = self._deleted_worktree()
+        env = self._env(
+            GITEA_ACTIVE_WORKTREE=missing,
+            GITEA_FORCE_TERMINAL_PROBE="1",
+        )
+        with patch.dict(os.environ, env):
+            res = mcp_server.gitea_resolve_task_capability(
+                task="create_pr", remote="prgs"
+            )
+            self.assertIn("GITEA_ACTIVE_WORKTREE", os.environ)
+        self.assertTrue(res.get("terminal_launcher_unhealthy"))
+        report = res.get("stale_binding_recovery") or {}
+        self.assertEqual(
+            report.get("classification"),
+            sbr.CLASSIFICATION_PROVABLY_STALE_MISSING_PATH,
+        )
+        self.assertFalse(report.get("recovery_performed"))
+
+    @patch("mcp_server.api_request", return_value={"login": "jcwalker3"})
+    @patch("mcp_server.get_auth_header", return_value="token author-pass")
+    def test_unverified_binding_is_never_cleared_by_reordering(self, _auth, _api):
+        # F1 must not weaken authorization: an existing, uncorroborated
+        # binding survives resolution untouched even with recovery forced.
+        existing = tempfile.mkdtemp(prefix="gitea-existing-worktree-")
+        self.addCleanup(shutil.rmtree, existing, ignore_errors=True)
+        env = self._env(
+            GITEA_ACTIVE_WORKTREE=existing,
+            GITEA_FORCE_TERMINAL_PROBE="1",
+            GITEA_FORCE_STALE_BINDING_RECOVERY="1",
+        )
+        with patch.dict(os.environ, env):
+            res = mcp_server.gitea_resolve_task_capability(
+                task="create_pr", remote="prgs"
+            )
+            self.assertEqual(os.environ.get("GITEA_ACTIVE_WORKTREE"), existing)
+        report = res.get("stale_binding_recovery") or {}
+        self.assertFalse(report.get("recovery_performed"))
+
+
+class TestF2PreflightPathVerification(_CapabilityHarness):
+    """F2: preflight and mutation contexts verify resolved paths alike."""
+
+    def test_preflight_and_mutation_context_agree_on_dead_binding(self):
+        missing = self._deleted_worktree()
+        env = self._env(GITEA_ACTIVE_WORKTREE=missing)
+        with patch.dict(os.environ, env):
+            preflight = mcp_server._resolve_preflight_workspace_path(None)
+            mutation = mcp_server._resolve_namespace_mutation_context(None)
+        self.assertEqual(preflight, mutation["workspace_path"])
+        self.assertNotEqual(preflight, os.path.realpath(missing))
+
+    def test_missing_explicit_worktree_never_reads_clean(self):
+        missing = self._deleted_worktree()
+        with patch.dict(os.environ, self._env()):
+            porcelain = mcp_server._get_workspace_porcelain(worktree_path=missing)
+        self.assertEqual(
+            porcelain, mcp_server.PREFLIGHT_WORKSPACE_UNAVAILABLE_PORCELAIN
+        )
+        # The sentinel parses as a tracked dirty entry — never clean.
+        self.assertTrue(mcp_server._parse_porcelain_entries(porcelain))
+
+    def test_workspace_deleted_during_evaluation_never_reads_clean(self):
+        # TOCTOU: resolution succeeded, then the path vanished before git ran.
+        missing = self._deleted_worktree()
+        with patch.dict(os.environ, self._env()):
+            with patch.object(
+                mcp_server,
+                "_resolve_preflight_workspace_path",
+                return_value=missing,
+            ):
+                porcelain = mcp_server._get_workspace_porcelain()
+        self.assertEqual(
+            porcelain, mcp_server.PREFLIGHT_WORKSPACE_UNAVAILABLE_PORCELAIN
+        )
+
+    def test_git_failure_never_reads_clean(self):
+        class _Failed:
+            returncode = 128
+            stdout = ""
+            stderr = "fatal: not a git repository"
+
+        with patch.dict(os.environ, self._env()):
+            with patch.object(
+                mcp_server.subprocess, "run", return_value=_Failed()
+            ):
+                porcelain = mcp_server._get_workspace_porcelain()
+        self.assertEqual(
+            porcelain, mcp_server.PREFLIGHT_WORKSPACE_UNAVAILABLE_PORCELAIN
+        )
+
+    def test_symlinked_binding_to_deleted_target_is_demoted(self):
+        target = tempfile.mkdtemp(prefix="gitea-symlink-target-")
+        holder = tempfile.mkdtemp(prefix="gitea-symlink-holder-")
+        self.addCleanup(shutil.rmtree, holder, ignore_errors=True)
+        link = os.path.join(holder, "worktree-link")
+        os.symlink(target, link)
+        shutil.rmtree(target)
+        demotions: list[str] = []
+        _path, source = nwb.resolve_namespace_workspace(
+            role_kind="reviewer",
+            process_project_root=os.getcwd(),
+            env={"GITEA_ACTIVE_WORKTREE": link},
+            demotions=demotions,
+            verify_paths=True,
+        )
+        self.assertEqual(source, "MCP server process root (default)")
+        self.assertEqual(len(demotions), 1)
+
+    def test_dead_binding_falls_through_to_live_role_binding(self):
+        # Path changes during evaluation: the dead candidate demotes at
+        # verification time and never resurrects over the live fallback.
+        alive = tempfile.mkdtemp(prefix="gitea-alive-worktree-")
+        self.addCleanup(shutil.rmtree, alive, ignore_errors=True)
+        missing = self._deleted_worktree()
+        path, source = nwb.resolve_namespace_workspace(
+            role_kind="reviewer",
+            process_project_root=os.getcwd(),
+            env={
+                "GITEA_ACTIVE_WORKTREE": missing,
+                "GITEA_REVIEWER_WORKTREE": alive,
+            },
+            verify_paths=True,
+        )
+        self.assertEqual(path, os.path.realpath(alive))
+        self.assertEqual(
+            source, "GITEA_REVIEWER_WORKTREE environment variable"
+        )
+
+
+class TestF3AffirmativeWorktreeEvidence(unittest.TestCase):
+    """F3: unknown worktree evidence must fail closed for crash orphans."""
+
+    def _comments(self) -> list[dict]:
+        stale = _now() - timedelta(hours=3)
+        body = leases.format_lease_body(
+            repo=REPO,
+            pr_number=701,
+            issue_number=699,
+            reviewer_identity="sysadmin",
+            profile="prgs-reviewer",
+            session_id="65664-4f248d213d60",
+            worktree="branches/review-pr-654",
+            phase="validation-start",
+            candidate_head=OLD_HEAD,
+            target_branch="master",
+            target_branch_sha="2" * 40,
+            last_activity=stale,
+            expires_at=stale + timedelta(minutes=120),
+        )
+        return [{
+            "id": 11131,
+            "body": body,
+            "user": {"login": "sysadmin"},
+            "author": "sysadmin",
+            "created_at": stale.isoformat(),
+            "updated_at": stale.isoformat(),
+        }]
+
+    def _assess(self, **kwargs):
+        defaults = dict(
+            pr_number=701,
+            current_head_sha=NEW_HEAD,
+            formal_reviews=[],
+            repo=REPO,
+            expected_repo=REPO,
+            requesting_session_id="fresh-controller",
+            controller_recovery_authorized=True,
+            owner_process_alive=False,
+        )
+        defaults.update(kwargs)
+        return leases.assess_obsolete_reviewer_comment_lease_cleanup(
+            self._comments(), **defaults
+        )
+
+    def test_unknown_worktree_evidence_fails_closed(self):
+        result = self._assess(worktree_exists=None, worktree_clean=None)
+        self.assertEqual(
+            result["classification"], "orphaned_expired_superseded_head"
+        )
+        self.assertFalse(result["cleanup_allowed"])
+        self.assertIn(
+            "affirmative safe evidence",
+            " ".join(result["fail_closed_reasons"]),
+        )
+
+    def test_unknown_cleanliness_with_existing_worktree_fails_closed(self):
+        result = self._assess(worktree_exists=True, worktree_clean=None)
+        self.assertFalse(result["cleanup_allowed"])
+
+    def test_affirmative_clean_worktree_is_eligible(self):
+        result = self._assess(worktree_exists=True, worktree_clean=True)
+        self.assertEqual(
+            result["classification"], "orphaned_expired_superseded_head"
+        )
+        self.assertTrue(result["cleanup_allowed"])
+
+    def test_affirmative_absent_worktree_is_eligible(self):
+        result = self._assess(worktree_exists=False, worktree_clean=None)
+        self.assertTrue(result["cleanup_allowed"])
+
+    def test_matrix_matches_diagnosis_gate(self):
+        # The cleanup matrix and the diagnosis path must agree: unknown
+        # evidence yields acquire-only, affirmative evidence yields cleanup.
+        diagnosis_unknown = leases.diagnose_reviewer_pr_lease_handoff(
+            self._comments(),
+            pr_number=701,
+            current_session_id=None,
+            current_reviewer_identity="fresh-reviewer",
+            current_head_sha=NEW_HEAD,
+            formal_reviews=[],
+            owner_process_alive=False,
+            worktree_exists=None,
+            worktree_clean=None,
+        )
+        assess_unknown = self._assess(worktree_exists=None, worktree_clean=None)
+        self.assertNotEqual(
+            diagnosis_unknown["next_action"],
+            "cleanup_obsolete_reviewer_comment_lease",
+        )
+        self.assertFalse(assess_unknown["cleanup_allowed"])
+
+
+class TestF4CrashShadowDurability(unittest.TestCase):
+    """F4: crash-orphan evidence survives the former 4h TTL boundary."""
+
+    SID = "82984-abcabcabcabc"
+
+    def setUp(self):
+        self._dir = tempfile.TemporaryDirectory()
+        self._env = patch.dict(
+            os.environ, {"GITEA_MCP_SESSION_STATE_DIR": self._dir.name}
+        )
+        self._env.start()
+        leases._SESSION_LEASE = None
+
+    def tearDown(self):
+        self._env.stop()
+        self._dir.cleanup()
+        leases._SESSION_LEASE = None
+
+    def _age_record(self, kind: str, hours: float, instance_id: str | None = None):
+        path = mss.state_file_path(kind=kind, instance_id=instance_id)
+        with open(path, encoding="utf-8") as fh:
+            envelope = json.load(fh)
+        stamp = (
+            (_now() - timedelta(hours=hours)).isoformat().replace("+00:00", "Z")
+        )
+        envelope["recorded_at"] = stamp
+        envelope["updated_at"] = stamp
+        envelope["payload"]["recorded_at"] = stamp
+        envelope["payload"]["updated_at"] = stamp
+        with open(path, "w", encoding="utf-8") as fh:
+            json.dump(envelope, fh)
+
+    def _save_shadow(self) -> None:
+        mss.save_state(
+            kind=mss.KIND_REVIEWER_SESSION_LEASE,
+            instance_id=self.SID,
+            payload={"session_id": self.SID, "owner_pid": os.getpid()},
+        )
+
+    def _load_shadow(self):
+        return mss.load_state(
+            kind=mss.KIND_REVIEWER_SESSION_LEASE, instance_id=self.SID
+        )
+
+    def test_shadow_loads_before_former_ttl_boundary(self):
+        self._save_shadow()
+        self._age_record(
+            mss.KIND_REVIEWER_SESSION_LEASE, hours=3.9, instance_id=self.SID
+        )
+        self.assertIsNotNone(self._load_shadow())
+
+    def test_shadow_loads_at_former_ttl_boundary(self):
+        self._save_shadow()
+        self._age_record(
+            mss.KIND_REVIEWER_SESSION_LEASE, hours=4.0, instance_id=self.SID
+        )
+        self.assertIsNotNone(self._load_shadow())
+
+    def test_shadow_loads_long_after_former_ttl_boundary(self):
+        self._save_shadow()
+        self._age_record(
+            mss.KIND_REVIEWER_SESSION_LEASE, hours=27.0, instance_id=self.SID
+        )
+        record = self._load_shadow()
+        self.assertIsNotNone(record)
+        self.assertEqual(record.get("session_id"), self.SID)
+
+    def test_stale_binding_audit_record_is_also_durable(self):
+        mss.save_state(
+            kind=mss.KIND_STALE_BINDING_RECOVERY,
+            payload={"cleared_env": "GITEA_ACTIVE_WORKTREE"},
+        )
+        self._age_record(mss.KIND_STALE_BINDING_RECOVERY, hours=27.0)
+        self.assertIsNotNone(
+            mss.load_state(kind=mss.KIND_STALE_BINDING_RECOVERY)
+        )
+
+    def test_non_recovery_kinds_keep_ttl(self):
+        mss.save_state(
+            kind=mss.KIND_WORKFLOW_LOAD, payload={"workflow_hash": "abc"}
+        )
+        self._age_record(mss.KIND_WORKFLOW_LOAD, hours=5.0)
+        self.assertIsNone(mss.load_state(kind=mss.KIND_WORKFLOW_LOAD))
+
+    def test_sanctioned_clear_is_the_terminal_reconciliation(self):
+        self._save_shadow()
+        self._age_record(
+            mss.KIND_REVIEWER_SESSION_LEASE, hours=27.0, instance_id=self.SID
+        )
+        mss.clear_state(
+            kind=mss.KIND_REVIEWER_SESSION_LEASE, instance_id=self.SID
+        )
+        self.assertIsNone(self._load_shadow())
+        self.assertEqual(
+            mss.list_states(kind=mss.KIND_REVIEWER_SESSION_LEASE), []
+        )
+
+    def test_crash_orphan_recovery_works_after_former_ttl(self):
+        # End to end: a crashed session's shadow still proves owner exit a
+        # day later.
+        leases.record_session_lease(
+            {
+                "pr_number": 701,
+                "session_id": self.SID,
+                "worktree": "branches/review-pr-654",
+                "candidate_head": OLD_HEAD,
+                "repo": REPO,
+                "comment_id": 11131,
+                "profile": "prgs-reviewer",
+                "reviewer_identity": "sysadmin",
+                "phase": "claimed",
+            },
+            lease_provenance={"source": "acquire", "comment_id": 11131},
+        )
+        leases._SESSION_LEASE = None  # simulated crash: no sanctioned clear
+        self._age_record(
+            mss.KIND_REVIEWER_SESSION_LEASE, hours=27.0, instance_id=self.SID
+        )
+        shadow = leases.load_session_lease_shadow(session_id=self.SID)
+        self.assertIsNotNone(shadow)
+        verdict = leases.assess_crashed_session_lease_orphan(
+            shadow,
+            lease={"session_id": self.SID},
+            current_pid=os.getpid() + 1,
+            pid_alive=False,
+        )
+        self.assertTrue(verdict["orphan_evidence"])
+        self.assertIs(verdict["owner_process_alive"], False)
+
+
+class TestF5ConcurrentSessionShadows(unittest.TestCase):
+    """F5: concurrent same-profile sessions keep distinct shadow records."""
+
+    SID_A = "11111-aaaaaaaaaaaa"
+    SID_B = "22222-bbbbbbbbbbbb"
+
+    def setUp(self):
+        self._dir = tempfile.TemporaryDirectory()
+        self._env = patch.dict(
+            os.environ, {"GITEA_MCP_SESSION_STATE_DIR": self._dir.name}
+        )
+        self._env.start()
+        leases._SESSION_LEASE = None
+
+    def tearDown(self):
+        self._env.stop()
+        self._dir.cleanup()
+        leases._SESSION_LEASE = None
+
+    def _lease(self, session_id: str, pr_number: int, head: str) -> dict:
+        return {
+            "pr_number": pr_number,
+            "session_id": session_id,
+            "worktree": f"branches/review-pr-{pr_number}-{session_id[:5]}",
+            "candidate_head": head,
+            "repo": REPO,
+            "comment_id": 11221,
+            "profile": "prgs-reviewer",
+            "reviewer_identity": "sysadmin",
+            "phase": "claimed",
+        }
+
+    def _record(self, lease: dict) -> None:
+        leases.record_session_lease(
+            lease,
+            lease_provenance={"source": "acquire", "comment_id": 11221},
+        )
+
+    def test_interleaved_sessions_do_not_overwrite_each_other(self):
+        self._record(self._lease(self.SID_A, 703, OLD_HEAD))
+        self._record(self._lease(self.SID_B, 701, NEW_HEAD))
+        # Session A heartbeats again after B wrote.
+        updated_a = self._lease(self.SID_A, 703, OLD_HEAD)
+        updated_a["phase"] = "validation-start"
+        self._record(updated_a)
+
+        shadow_a = leases.load_session_lease_shadow(session_id=self.SID_A)
+        shadow_b = leases.load_session_lease_shadow(session_id=self.SID_B)
+        self.assertEqual(shadow_a.get("session_id"), self.SID_A)
+        self.assertEqual(shadow_a.get("pr_number"), 703)
+        self.assertEqual(shadow_a.get("phase"), "validation-start")
+        self.assertEqual(shadow_b.get("session_id"), self.SID_B)
+        self.assertEqual(shadow_b.get("pr_number"), 701)
+        self.assertEqual(shadow_b.get("candidate_head"), NEW_HEAD)
+
+    def test_shadow_lookup_never_misattributes(self):
+        self._record(self._lease(self.SID_A, 703, OLD_HEAD))
+        self.assertIsNone(
+            leases.load_session_lease_shadow(session_id=self.SID_B)
+        )
+        verdict = leases.assess_crashed_session_lease_orphan(
+            leases.load_session_lease_shadow(session_id=self.SID_A),
+            lease={"session_id": self.SID_B},
+            pid_alive=False,
+        )
+        self.assertFalse(verdict["orphan_evidence"])
+
+    def test_clearing_one_session_preserves_the_other(self):
+        self._record(self._lease(self.SID_A, 703, OLD_HEAD))
+        self._record(self._lease(self.SID_B, 701, NEW_HEAD))
+        # Sanctioned clear of B (the currently recorded in-memory lease).
+        leases.clear_session_lease()
+        self.assertIsNone(
+            leases.load_session_lease_shadow(session_id=self.SID_B)
+        )
+        shadow_a = leases.load_session_lease_shadow(session_id=self.SID_A)
+        self.assertIsNotNone(shadow_a)
+        self.assertEqual(shadow_a.get("session_id"), self.SID_A)
+
+    def test_reconnected_process_recovers_by_session_id(self):
+        self._record(self._lease(self.SID_A, 703, OLD_HEAD))
+        self._record(self._lease(self.SID_B, 701, NEW_HEAD))
+        # Simulated crash + reconnect: in-memory state is gone, durable
+        # records remain enumerable and individually attributable.
+        leases._SESSION_LEASE = None
+        records = mss.list_states(kind=mss.KIND_REVIEWER_SESSION_LEASE)
+        self.assertEqual(
+            sorted(r.get("session_id") for r in records),
+            sorted([self.SID_A, self.SID_B]),
+        )
+        shadow = leases.load_session_lease_shadow(session_id=self.SID_B)
+        self.assertEqual(shadow.get("pr_number"), 701)
+
+    def test_legacy_single_slot_record_still_resolves_by_session_id(self):
+        # Upgrade path: a record written by pre-F5 code (no instance key)
+        # remains usable when its payload names the requested session.
+        mss.save_state(
+            kind=mss.KIND_REVIEWER_SESSION_LEASE,
+            payload={"session_id": self.SID_A, "owner_pid": os.getpid()},
+        )
+        shadow = leases.load_session_lease_shadow(session_id=self.SID_A)
+        self.assertIsNotNone(shadow)
+        self.assertIsNone(
+            leases.load_session_lease_shadow(session_id=self.SID_B)
+        )
+
+
+class TestF6AuditBeforeClear(_CapabilityHarness):
+    """F6: the durable audit record is persisted before the env clears."""
+
+    def _recovery_env(self, missing: str) -> dict:
+        return self._env(
+            GITEA_ACTIVE_WORKTREE=missing,
+            GITEA_FORCE_STALE_BINDING_RECOVERY="1",
+        )
+
+    def test_audit_write_failure_blocks_the_clear(self):
+        missing = self._deleted_worktree()
+        with patch.dict(os.environ, self._recovery_env(missing)):
+            with patch.object(
+                mss, "save_state", side_effect=OSError("disk full")
+            ):
+                report = mcp_server._assess_stale_active_binding(
+                    auto_recover=True
+                )
+            self.assertEqual(os.environ.get("GITEA_ACTIVE_WORKTREE"), missing)
+        self.assertFalse(report["recovery_performed"])
+        self.assertIs(report.get("audit_persisted"), False)
+        self.assertTrue(report.get("audit_write_failed"))
+        self.assertIn("NOT cleared", " ".join(report.get("reasons") or []))
+
+    def test_retry_after_audit_failure_recovers(self):
+        missing = self._deleted_worktree()
+        with patch.dict(os.environ, self._recovery_env(missing)):
+            with patch.object(
+                mss, "save_state", side_effect=OSError("disk full")
+            ):
+                first = mcp_server._assess_stale_active_binding(
+                    auto_recover=True
+                )
+            self.assertFalse(first["recovery_performed"])
+            # Persistence recovered; the retry clears with a durable audit.
+            second = mcp_server._assess_stale_active_binding(auto_recover=True)
+            self.assertTrue(second["recovery_performed"])
+            self.assertIs(second.get("audit_persisted"), True)
+            self.assertNotIn("GITEA_ACTIVE_WORKTREE", os.environ)
+            audit = mss.load_state(kind=mss.KIND_STALE_BINDING_RECOVERY)
+        self.assertIsNotNone(audit)
+        self.assertEqual(audit.get("recovery_status"), "performed")
+        self.assertEqual(audit.get("cleared_value"), missing)
+
+    def test_audit_record_exists_before_env_clear(self):
+        missing = self._deleted_worktree()
+        observed: list[tuple[str | None, str | None]] = []
+        real_save = mss.save_state
+
+        def _spy(**kwargs):
+            observed.append(
+                (
+                    (kwargs.get("payload") or {}).get("recovery_status"),
+                    os.environ.get("GITEA_ACTIVE_WORKTREE"),
+                )
+            )
+            return real_save(**kwargs)
+
+        with patch.dict(os.environ, self._recovery_env(missing)):
+            with patch.object(mss, "save_state", side_effect=_spy):
+                report = mcp_server._assess_stale_active_binding(
+                    auto_recover=True
+                )
+        self.assertTrue(report["recovery_performed"])
+        self.assertGreaterEqual(len(observed), 2)
+        pending_status, env_at_pending = observed[0]
+        performed_status, env_at_performed = observed[-1]
+        # Ordering proof: the binding was still present while the pending
+        # audit persisted, and gone by the time the performed status wrote.
+        self.assertEqual(pending_status, "pending")
+        self.assertEqual(env_at_pending, missing)
+        self.assertEqual(performed_status, "performed")
+        self.assertIsNone(env_at_performed)
+
+    def test_recovery_is_idempotent_after_success(self):
+        missing = self._deleted_worktree()
+        with patch.dict(os.environ, self._recovery_env(missing)):
+            first = mcp_server._assess_stale_active_binding(auto_recover=True)
+            second = mcp_server._assess_stale_active_binding(auto_recover=True)
+        self.assertTrue(first["recovery_performed"])
+        self.assertEqual(second["classification"], sbr.CLASSIFICATION_UNBOUND)
+        self.assertFalse(second["recovery_performed"])
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_issue_702_stale_binding_lease_recovery.py

@@ -0,0 +1,517 @@
+"""Regression tests for #702: stale runtime binding + orphaned durable lease.
+
+Reproduces the PR #701 incident (lease 65664-4f248d213d60, comments
+11129/11131): the MCP daemon crashed without teardown, destroying the
+in-memory session lease while the durable comment lease survived, and the
+auto-reconnected daemon inherited a stale ``GITEA_ACTIVE_WORKTREE`` binding
+(``branches/review-pr-654``) from its parent environment.
+
+Covers the five mandated scenarios:
+
+1. lost in-session leases  — durable shadow survives a crash and yields
+   provable owner-process evidence
+2. old-head leases         — expired superseded-head lease with no terminal
+   review becomes recoverable only with orphan evidence + controller authority
+3. runtime/worktree mismatch — env bindings to deleted worktrees are demoted,
+   never silently bound
+4. managed reconnect       — boot-inherited uncorroborated bindings are
+   surfaced for managed recovery; provably stale ones are clear-eligible
+5. safe expiry             — pre-expiry stays fail-closed wait (no steal);
+   canonical expiry unlocks acquisition and guarded cleanup
+"""
+
+from __future__ import annotations
+
+import os
+import sys
+import unittest
+from datetime import datetime, timedelta, timezone
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+import namespace_workspace_binding as nwb  # noqa: E402
+import reviewer_pr_lease as leases  # noqa: E402
+import stale_binding_recovery as sbr  # noqa: E402
+
+# PR #701 incident fixtures.
+OLD_HEAD = "b4d0cb22e452a07c8e816745c704ddb0f43edf0b"
+NEW_HEAD = "6b675f5c834b41f9d74e8a54294ff44dddf28ae4"
+CRASHED_SESSION = "65664-4f248d213d60"
+LEASE_COMMENT = 11131
+REPO = "Scaled-Tech-Consulting/Gitea-Tools"
+PR = 701
+ISSUE = 699
+LEASE_WORKTREE = "branches/review-fix-issue-699-structured-auth-mcp-errors"
+
+
+def _now() -> datetime:
+    return datetime.now(timezone.utc)
+
+
+def _lease_comment(
+    *,
+    phase: str = "validation-start",
+    candidate_head: str = OLD_HEAD,
+    session_id: str = CRASHED_SESSION,
+    comment_id: int = LEASE_COMMENT,
+    last_activity: datetime | None = None,
+    expires_at: datetime | None = None,
+    worktree: str = LEASE_WORKTREE,
+) -> dict:
+    stamp = last_activity or _now()
+    body = leases.format_lease_body(
+        repo=REPO,
+        pr_number=PR,
+        issue_number=ISSUE,
+        reviewer_identity="sysadmin",
+        profile="prgs-reviewer",
+        session_id=session_id,
+        worktree=worktree,
+        phase=phase,
+        candidate_head=candidate_head,
+        target_branch="master",
+        target_branch_sha="2" * 40,
+        last_activity=stamp,
+        expires_at=expires_at,
+    )
+    return {
+        "id": comment_id,
+        "body": body,
+        "user": {"login": "sysadmin"},
+        "author": "sysadmin",
+        "created_at": stamp.isoformat(),
+        "updated_at": stamp.isoformat(),
+    }
+
+
+def _expired_superseded_comments() -> list[dict]:
+    stale = _now() - timedelta(hours=3)
+    return [_lease_comment(
+        last_activity=stale,
+        expires_at=stale + timedelta(minutes=120),
+    )]
+
+
+def _fresh_superseded_comments() -> list[dict]:
+    recent = _now() - timedelta(minutes=10)
+    return [_lease_comment(
+        last_activity=recent,
+        expires_at=recent + timedelta(minutes=120),
+    )]
+
+
+class TestLostInSessionLeaseShadow(unittest.TestCase):
+    """Scenario 1: the durable shadow survives a daemon crash (#702 AC3)."""
+
+    def setUp(self):
+        leases._SESSION_LEASE = None
+
+    def tearDown(self):
+        leases._SESSION_LEASE = None
+
+    def _record(self) -> dict:
+        return leases.record_session_lease(
+            {
+                "pr_number": PR,
+                "issue_number": ISSUE,
+                "session_id": CRASHED_SESSION,
+                "reviewer_identity": "sysadmin",
+                "profile": "prgs-reviewer",
+                "worktree": LEASE_WORKTREE,
+                "phase": "claimed",
+                "candidate_head": OLD_HEAD,
+                "repo": REPO,
+                "comment_id": LEASE_COMMENT,
+            },
+            lease_provenance={"source": "acquire", "comment_id": LEASE_COMMENT},
+        )
+
+    def test_shadow_written_on_record_and_survives_simulated_crash(self):
+        self._record()
+        # Simulated unhandled crash: the in-memory dict dies with the process
+        # but the sanctioned clear path never runs.
+        leases._SESSION_LEASE = None
+        shadow = leases.load_session_lease_shadow()
+        self.assertIsNotNone(shadow)
+        self.assertEqual(shadow.get("session_id"), CRASHED_SESSION)
+        self.assertEqual(shadow.get("pr_number"), PR)
+        self.assertEqual(int(shadow.get("owner_pid")), os.getpid())
+
+    def test_sanctioned_clear_removes_shadow(self):
+        self._record()
+        leases.clear_session_lease()
+        self.assertIsNone(leases.load_session_lease_shadow())
+
+    def test_orphan_assessment_dead_owner_pid_proves_exit(self):
+        self._record()
+        leases._SESSION_LEASE = None
+        shadow = leases.load_session_lease_shadow()
+        lease = {"session_id": CRASHED_SESSION}
+        verdict = leases.assess_crashed_session_lease_orphan(
+            shadow, lease=lease, current_pid=os.getpid() + 1, pid_alive=False
+        )
+        self.assertTrue(verdict["orphan_evidence"])
+        self.assertIs(verdict["owner_process_alive"], False)
+
+    def test_orphan_assessment_alive_pid_is_not_ownership_proof(self):
+        self._record()
+        shadow = leases.load_session_lease_shadow()
+        verdict = leases.assess_crashed_session_lease_orphan(
+            shadow,
+            lease={"session_id": CRASHED_SESSION},
+            current_pid=os.getpid() + 1,
+            pid_alive=True,
+        )
+        self.assertFalse(verdict["orphan_evidence"])
+        self.assertIsNone(verdict["owner_process_alive"])
+
+    def test_orphan_assessment_session_mismatch_proves_nothing(self):
+        self._record()
+        shadow = leases.load_session_lease_shadow()
+        verdict = leases.assess_crashed_session_lease_orphan(
+            shadow, lease={"session_id": "other-999"}, pid_alive=False
+        )
+        self.assertFalse(verdict["orphan_evidence"])
+        self.assertIsNone(verdict["owner_process_alive"])
+
+    def test_orphan_assessment_without_shadow_is_unknown(self):
+        verdict = leases.assess_crashed_session_lease_orphan(
+            None, lease={"session_id": CRASHED_SESSION}
+        )
+        self.assertFalse(verdict["orphan_evidence"])
+        self.assertIsNone(verdict["owner_process_alive"])
+
+
+class TestOldHeadLeaseCleanup(unittest.TestCase):
+    """Scenario 2: expired superseded-head lease with no terminal review."""
+
+    def _assess(self, comments, **kwargs):
+        defaults = dict(
+            pr_number=PR,
+            current_head_sha=NEW_HEAD,
+            formal_reviews=[],
+            repo=REPO,
+            expected_repo=REPO,
+            requesting_session_id="fresh-controller",
+            controller_recovery_authorized=True,
+            worktree_exists=True,
+            worktree_clean=True,
+            owner_process_alive=False,
+        )
+        defaults.update(kwargs)
+        return leases.assess_obsolete_reviewer_comment_lease_cleanup(
+            comments, **defaults
+        )
+
+    def test_expired_orphan_with_full_evidence_is_cleanup_eligible(self):
+        result = self._assess(_expired_superseded_comments())
+        self.assertEqual(result["classification"], "orphaned_expired_superseded_head")
+        self.assertTrue(result["cleanup_allowed"])
+        self.assertIn("phase: released", result["release_body"] or "")
+        self.assertEqual(
+            result["exact_next_action"], "cleanup_obsolete_reviewer_comment_lease"
+        )
+
+    def test_expired_orphan_without_owner_evidence_fails_closed(self):
+        result = self._assess(
+            _expired_superseded_comments(), owner_process_alive=None
+        )
+        self.assertFalse(result["cleanup_allowed"])
+        self.assertIn(
+            "provable owner-process-exit evidence",
+            " ".join(result["fail_closed_reasons"]),
+        )
+
+    def test_expired_orphan_without_controller_authority_fails_closed(self):
+        result = self._assess(
+            _expired_superseded_comments(), controller_recovery_authorized=False
+        )
+        self.assertFalse(result["cleanup_allowed"])
+
+    def test_expired_orphan_with_dirty_worktree_fails_closed(self):
+        result = self._assess(
+            _expired_superseded_comments(),
+            worktree_clean=False,
+            worktree_has_unpreserved_work=True,
+        )
+        self.assertFalse(result["cleanup_allowed"])
+
+    def test_unexpired_superseded_no_terminal_stays_ambiguous_wait(self):
+        # Regression guard: pre-expiry there is still no steal path.
+        result = self._assess(_fresh_superseded_comments())
+        self.assertEqual(result["classification"], "ambiguous_conflicting_evidence")
+        self.assertFalse(result["cleanup_allowed"])
+        self.assertEqual(result["exact_next_action"], "wait")
+
+
+class TestRuntimeWorktreeMismatch(unittest.TestCase):
+    """Scenario 3: env bindings to deleted worktrees are demoted (#702 AC2)."""
+
+    def test_missing_active_env_binding_is_demoted(self):
+        demotions: list[str] = []
+        missing = "/nonexistent/branches/review-pr-654"
+        path, source = nwb.resolve_namespace_workspace(
+            role_kind="reviewer",
+            process_project_root=os.getcwd(),
+            env={"GITEA_ACTIVE_WORKTREE": missing},
+            demotions=demotions,
+            verify_paths=True,
+        )
+        self.assertEqual(source, "MCP server process root (default)")
+        self.assertEqual(len(demotions), 1)
+        self.assertIn("no longer exists", demotions[0])
+
+    def test_missing_active_falls_through_to_existing_role_env(self):
+        existing = os.getcwd()
+        path, source = nwb.resolve_namespace_workspace(
+            role_kind="reviewer",
+            process_project_root="/tmp",
+            env={
+                "GITEA_ACTIVE_WORKTREE": "/nonexistent/branches/review-pr-654",
+                "GITEA_REVIEWER_WORKTREE": existing,
+            },
+            verify_paths=True,
+        )
+        self.assertEqual(path, os.path.realpath(existing))
+        self.assertEqual(source, "GITEA_REVIEWER_WORKTREE environment variable")
+
+    def test_existing_active_env_binding_still_wins(self):
+        existing = os.getcwd()
+        path, source = nwb.resolve_namespace_workspace(
+            role_kind="reviewer",
+            process_project_root="/tmp",
+            env={"GITEA_ACTIVE_WORKTREE": existing},
+            verify_paths=True,
+        )
+        self.assertEqual(path, os.path.realpath(existing))
+        self.assertEqual(source, "GITEA_ACTIVE_WORKTREE environment variable")
+
+    def test_explicit_worktree_path_argument_is_never_demoted(self):
+        missing = "/nonexistent/branches/explicit"
+        path, source = nwb.resolve_namespace_workspace(
+            role_kind="reviewer",
+            worktree_path=missing,
+            process_project_root="/tmp",
+            env={},
+            verify_paths=True,
+        )
+        self.assertEqual(source, "worktree_path argument")
+
+    def test_mutation_context_reports_demotion_in_ignored_bindings(self):
+        ctx = nwb.resolve_namespace_mutation_context(
+            role_kind="reviewer",
+            worktree_path=None,
+            process_project_root=os.getcwd(),
+            env={"GITEA_ACTIVE_WORKTREE": "/nonexistent/branches/review-pr-654"},
+        )
+        joined = " ".join(ctx["ignored_bindings"])
+        self.assertIn("stale binding, #702", joined)
+
+
+class TestManagedReconnectRecovery(unittest.TestCase):
+    """Scenario 4: boot-inherited bindings and the sanctioned recovery plan."""
+
+    def test_uncorroborated_inherited_reviewer_binding_is_unverified(self):
+        classification = sbr.classify_active_worktree_binding(
+            active_value=os.getcwd(),
+            role_env_value=None,
+            session_lease_worktree=None,
+            boot_inherited=True,
+            path_exists=True,
+            role_kind="reviewer",
+        )
+        self.assertEqual(
+            classification["classification"], sbr.CLASSIFICATION_UNVERIFIED_INHERITED
+        )
+        self.assertFalse(classification["clear_eligible"])
+        plan = sbr.plan_recovery(classification)
+        self.assertFalse(plan["clear_allowed"])
+        self.assertIn("managed", plan["exact_next_action"])
+        self.assertIn("do not clear or rewrite", plan["exact_next_action"])
+
+    def test_missing_path_binding_is_provably_stale_and_clear_eligible(self):
+        classification = sbr.classify_active_worktree_binding(
+            active_value="/nonexistent/branches/review-pr-654",
+            boot_inherited=True,
+            path_exists=False,
+            role_kind="reviewer",
+        )
+        self.assertEqual(
+            classification["classification"],
+            sbr.CLASSIFICATION_PROVABLY_STALE_MISSING_PATH,
+        )
+        plan = sbr.plan_recovery(classification)
+        self.assertTrue(plan["clear_allowed"])
+
+    def test_inherited_binding_superseded_by_session_lease_is_clear_eligible(self):
+        classification = sbr.classify_active_worktree_binding(
+            active_value="/tmp",
+            session_lease_worktree=os.getcwd(),
+            boot_inherited=True,
+            path_exists=True,
+            role_kind="reviewer",
+        )
+        self.assertEqual(
+            classification["classification"],
+            sbr.CLASSIFICATION_SUPERSEDED_BY_SESSION_LEASE,
+        )
+        self.assertTrue(sbr.plan_recovery(classification)["clear_allowed"])
+
+    def test_post_boot_binding_conflict_is_surfaced_not_cleared(self):
+        classification = sbr.classify_active_worktree_binding(
+            active_value="/tmp",
+            session_lease_worktree=os.getcwd(),
+            boot_inherited=False,
+            path_exists=True,
+            role_kind="reviewer",
+        )
+        self.assertEqual(
+            classification["classification"], sbr.CLASSIFICATION_UNVERIFIED_INHERITED
+        )
+        self.assertFalse(sbr.plan_recovery(classification)["clear_allowed"])
+
+    def test_corroborated_bindings_are_untouched(self):
+        for kwargs in (
+            dict(role_env_value=os.getcwd()),
+            dict(session_lease_worktree=os.getcwd()),
+        ):
+            classification = sbr.classify_active_worktree_binding(
+                active_value=os.getcwd(),
+                boot_inherited=True,
+                path_exists=True,
+                role_kind="reviewer",
+                **kwargs,
+            )
+            self.assertEqual(
+                classification["classification"], sbr.CLASSIFICATION_CORROBORATED
+            )
+            self.assertFalse(sbr.plan_recovery(classification)["clear_allowed"])
+
+    def test_author_inherited_binding_stays_corroborated(self):
+        classification = sbr.classify_active_worktree_binding(
+            active_value=os.getcwd(),
+            boot_inherited=True,
+            path_exists=True,
+            role_kind="author",
+        )
+        self.assertEqual(
+            classification["classification"], sbr.CLASSIFICATION_CORROBORATED
+        )
+
+    def test_apply_recovery_clears_env_only_for_authorized_plan(self):
+        env = {"GITEA_ACTIVE_WORKTREE": "/nonexistent/branches/review-pr-654"}
+        plan = sbr.plan_recovery(
+            sbr.classify_active_worktree_binding(
+                active_value=env["GITEA_ACTIVE_WORKTREE"],
+                boot_inherited=True,
+                path_exists=False,
+                role_kind="reviewer",
+            )
+        )
+        applied = sbr.apply_recovery(plan, env=env)
+        self.assertTrue(applied["performed"])
+        self.assertNotIn("GITEA_ACTIVE_WORKTREE", env)
+        self.assertIn("review-pr-654", applied["cleared_value"])
+
+    def test_apply_recovery_refuses_unauthorized_plan(self):
+        env = {"GITEA_ACTIVE_WORKTREE": os.getcwd()}
+        plan = sbr.plan_recovery(
+            sbr.classify_active_worktree_binding(
+                active_value=env["GITEA_ACTIVE_WORKTREE"],
+                boot_inherited=True,
+                path_exists=True,
+                role_kind="reviewer",
+            )
+        )
+        applied = sbr.apply_recovery(plan, env=env)
+        self.assertFalse(applied["performed"])
+        self.assertIn("GITEA_ACTIVE_WORKTREE", env)
+
+
+class TestSafeExpiryDiagnosis(unittest.TestCase):
+    """Scenario 5: canonical expiry flips wait into acquire/guarded cleanup."""
+
+    def _diagnose(self, comments, **kwargs):
+        defaults = dict(
+            pr_number=PR,
+            current_session_id=None,
+            current_reviewer_identity="fresh-reviewer",
+            current_head_sha=NEW_HEAD,
+            formal_reviews=[],
+        )
+        defaults.update(kwargs)
+        return leases.diagnose_reviewer_pr_lease_handoff(comments, **defaults)
+
+    def setUp(self):
+        leases._SESSION_LEASE = None
+
+    def test_pre_expiry_superseded_no_terminal_stays_wait(self):
+        diagnosis = self._diagnose(_fresh_superseded_comments())
+        self.assertEqual(
+            diagnosis["classification"], "ambiguous_conflicting_evidence"
+        )
+        self.assertEqual(diagnosis["next_action"], "wait")
+
+    def test_post_expiry_without_orphan_evidence_unlocks_acquire(self):
+        diagnosis = self._diagnose(_expired_superseded_comments())
+        self.assertEqual(
+            diagnosis["classification"], "orphaned_expired_superseded_head"
+        )
+        self.assertEqual(diagnosis["next_action"], "acquire")
+
+    def test_post_expiry_with_orphan_evidence_offers_guarded_cleanup(self):
+        diagnosis = self._diagnose(
+            _expired_superseded_comments(),
+            owner_process_alive=False,
+            worktree_clean=True,
+            worktree_exists=True,
+        )
+        self.assertEqual(
+            diagnosis["classification"], "orphaned_expired_superseded_head"
+        )
+        self.assertEqual(
+            diagnosis["next_action"], "cleanup_obsolete_reviewer_comment_lease"
+        )
+
+    def test_expired_lease_no_longer_blocks_fresh_acquisition(self):
+        assessment = leases.assess_acquire_lease(
+            _expired_superseded_comments(),
+            pr_number=PR,
+            reviewer_identity="fresh-reviewer",
+            profile="prgs-reviewer",
+            session_id="99999-fresh",
+            repo=REPO,
+            issue_number=ISSUE,
+            worktree="branches/review-pr-701-fresh",
+            candidate_head=NEW_HEAD,
+            target_branch="master",
+            target_branch_sha="2" * 40,
+        )
+        self.assertTrue(assessment.get("acquire_allowed"))
+
+    def test_unparseable_expiry_fails_closed_in_cleanup(self):
+        comment = _lease_comment(
+            last_activity=_now() - timedelta(hours=3), expires_at=None
+        )
+        comment["body"] = comment["body"].replace(
+            "expires_at: ", "expires_at: not-a-timestamp"
+        )
+        result = leases.assess_obsolete_reviewer_comment_lease_cleanup(
+            [comment],
+            pr_number=PR,
+            current_head_sha=NEW_HEAD,
+            formal_reviews=[],
+            repo=REPO,
+            expected_repo=REPO,
+            requesting_session_id="fresh-controller",
+            controller_recovery_authorized=True,
+            worktree_exists=True,
+            worktree_clean=True,
+            owner_process_alive=False,
+        )
+        self.assertFalse(result["cleanup_allowed"])
+
+
+if __name__ == "__main__":
+    unittest.main()