Merge branch 'master' into fix/issue-702-stale-binding-lease-recovery

anti_stomp_preflight.py

@@ -0,0 +1,807 @@
+"""Common anti-stomp preflight for every MCP mutation tool (#604).
+
+Even with leases, mutation tools need a **shared** preflight that prevents
+stale sessions, wrong worktrees, wrong repos, old prompts, terminal locks,
+foreign leases, contaminated approvals, and root-checkout mutations from
+slipping through.
+
+This module is the pure assessment core. Callers (MCP mutation entrypoints)
+gather live facts and pass them in — nothing here performs git, network, or
+durable-state I/O. Existing happy-path guards remain authoritative; this
+module composes them into one typed, fail-closed result.
+
+Required checks (issue #604):
+
+* repo/org verification
+* profile/role verification
+* root checkout clean and not used for mutation (when role requires branches/)
+* worktree under branches when required
+* active lease ownership (when lease is required for the mutation)
+* terminal lock status (when applicable)
+* expected head SHA (when pinned)
+* stale runtime status
+* workflow hash (when a workflow load is required)
+* source contamination status
+* no manual state/mtime/source-file bypass
+
+Failure returns a typed blocker and an exact next action. There is **no**
+agent-facing bypass flag.
+"""
+
+from __future__ import annotations
+
+from typing import Any
+
+import author_mutation_worktree
+import master_parity_gate
+import remote_repo_guard
+import root_checkout_guard
+import stable_branch_push_guard
+
+# ── public constants ──────────────────────────────────────────────────────────
+
+# Typed blocker kinds returned in the structured result.
+BLOCKER_WRONG_REPO = "wrong_repo"
+BLOCKER_WRONG_ROLE = "wrong_role"
+BLOCKER_ROOT_CHECKOUT = "root_checkout_mutation"
+BLOCKER_WRONG_WORKTREE = "wrong_worktree"
+BLOCKER_FOREIGN_LEASE = "foreign_lease"
+BLOCKER_TERMINAL_LOCK = "terminal_lock"
+BLOCKER_HEAD_SHA = "head_sha_mismatch"
+BLOCKER_STALE_RUNTIME = "stale_runtime"
+BLOCKER_WORKFLOW_HASH = "workflow_hash"
+BLOCKER_SOURCE_CONTAMINATION = "source_contamination"
+BLOCKER_MANUAL_BYPASS = "manual_bypass"
+
+BLOCKER_KINDS = frozenset({
+    BLOCKER_WRONG_REPO,
+    BLOCKER_WRONG_ROLE,
+    BLOCKER_ROOT_CHECKOUT,
+    BLOCKER_WRONG_WORKTREE,
+    BLOCKER_FOREIGN_LEASE,
+    BLOCKER_TERMINAL_LOCK,
+    BLOCKER_HEAD_SHA,
+    BLOCKER_STALE_RUNTIME,
+    BLOCKER_WORKFLOW_HASH,
+    BLOCKER_SOURCE_CONTAMINATION,
+    BLOCKER_MANUAL_BYPASS,
+})
+
+# Mutation tasks that must invoke the shared anti-stomp preflight before
+# acting (issue #604 AC1). Every member must appear as a live task= kwarg
+# to verify_preflight_purity / _run_anti_stomp_preflight (or the review
+# anti_task map) in gitea_mcp_server.py. Inventory↔wiring tests fail if
+# a declared task is not wired.
+MUTATION_TASKS = frozenset({
+    "create_issue",
+    "comment_issue",
+    "close_issue",
+    "mark_issue",
+    "lock_issue",
+    "set_issue_labels",
+    "create_label",
+    "create_pr",
+    "close_pr",
+    "edit_pr",
+    "commit_files",
+    "gitea_commit_files",
+    "delete_branch",
+    "cleanup_merged_pr_branch",
+    "cleanup_stale_claims",
+    "reconcile_merged_cleanups",
+    "reconcile_already_landed_pr",
+    "reconcile_close_superseded_pr",
+    "post_heartbeat",
+    "acquire_reviewer_pr_lease",
+    "gitea_acquire_reviewer_pr_lease",
+    "adopt_merger_pr_lease",
+    "review_pr",
+    "submit_pr_review",
+    "approve_pr",
+    "request_changes_pr",
+    "merge_pr",
+})
+
+# Intentionally excluded from MUTATION_TASKS. Each has a dedicated
+# fail-closed gate that preserves decision-lock ownership, workflow-hash,
+# head-SHA, and repository consistency. Do not re-add without either
+# wiring shared preflight or updating this rationale (#604 Blocker B).
+DEDICATED_GATE_MUTATIONS: dict[str, str] = {
+    "mark_final_review_decision": (
+        "Local review-decision lock only. Enforced by session lock ownership, "
+        "workflow-hash, expected head SHA, PR work lease, eligibility, and "
+        "terminal-lock gates. No Gitea review POST; shared anti-stomp would "
+        "duplicate without side-effect-ordering value."
+    ),
+    "save_review_draft": (
+        "Local session-state draft save with live PR head/base consistency "
+        "checks. Not a Gitea review/merge mutation; dedicated head-SHA and "
+        "worktree resolution gates apply."
+    ),
+    "resume_review_draft": (
+        "Live-state resume with terminal lock, lease ownership, head/base SHA, "
+        "and parity checks. When submit=True, delegates to gitea_submit_pr_review "
+        "which runs shared anti-stomp before the Gitea review POST."
+    ),
+    "cleanup_stale_review_decision_lock": (
+        "Moot-lock cleanup with identity match, live PR merged/closed proof, "
+        "and reviewer capability gate (#594). Distinct from shared anti-stomp."
+    ),
+    "gitea_cleanup_stale_review_decision_lock": (
+        "Alias of cleanup_stale_review_decision_lock; dedicated #594 path."
+    ),
+    "heartbeat_reviewer_pr_lease": (
+        "Lease heartbeat posts via verify_preflight_purity(task='review_pr') "
+        "plus in-session lease ownership checks; not a separate mutation class."
+    ),
+    "release_reviewer_pr_lease": (
+        "Lease release uses workspace binding + ownership checks; posts only "
+        "when the session owns the active lease."
+    ),
+}
+
+# Roles that must mutate from a branches/ worktree (not the control checkout).
+_BRANCHES_REQUIRED_ROLES = frozenset({"author"})
+
+# Reviewer/merger mutations that require an owned lease + head pinning when
+# the caller supplies those facts.
+_LEASE_AWARE_TASKS = frozenset({
+    "review_pr",
+    "submit_pr_review",
+    "approve_pr",
+    "request_changes_pr",
+    "merge_pr",
+    "acquire_reviewer_pr_lease",
+    "gitea_acquire_reviewer_pr_lease",
+    "adopt_merger_pr_lease",
+})
+
+_NEXT_ACTIONS: dict[str, str] = {
+    BLOCKER_WRONG_REPO: (
+        "Pass explicit org= and repo= matching the local git remote "
+        "(e.g. org=Scaled-Tech-Consulting repo=Gitea-Tools) and retry."
+    ),
+    BLOCKER_WRONG_ROLE: (
+        "Call gitea_resolve_task_capability, switch to the required "
+        "namespace/profile, re-verify with gitea_whoami, then retry."
+    ),
+    BLOCKER_ROOT_CHECKOUT: (
+        "Leave the root control checkout on clean master; create or switch "
+        "to a session-owned worktree under branches/ and retry the mutation "
+        "with worktree_path set."
+    ),
+    BLOCKER_WRONG_WORKTREE: (
+        "Create or bind a session-owned worktree under branches/, set "
+        "worktree_path (or GITEA_ACTIVE_WORKTREE), and retry."
+    ),
+    BLOCKER_FOREIGN_LEASE: (
+        "Stop. Do not stomp a foreign lease. Wait for expiry, request "
+        "takeover through the sanctioned path, or hand off to the owner."
+    ),
+    BLOCKER_TERMINAL_LOCK: (
+        "Stop. A terminal review-decision lock is active for this head. "
+        "Do not re-approve/merge; follow the #332/#620 recovery path."
+    ),
+    BLOCKER_HEAD_SHA: (
+        "Re-fetch the live PR head with gitea_view_pr, re-pin "
+        "expected_head_sha to the current head, re-validate, then retry."
+    ),
+    BLOCKER_STALE_RUNTIME: (
+        "Restart the Gitea MCP server so it reloads master's capability "
+        "gates, re-run gitea_whoami + gitea_resolve_task_capability, then retry."
+    ),
+    BLOCKER_WORKFLOW_HASH: (
+        "Reload the canonical workflow via gitea_load_review_workflow, then "
+        "rerun the full review-merge workflow from inventory (no approve/merge replay)."
+    ),
+    BLOCKER_SOURCE_CONTAMINATION: (
+        "Stop. Session is source-contaminated. Hand off to a reconciler for "
+        "audit/clear; do not clear markers by deleting session-state files."
+    ),
+    BLOCKER_MANUAL_BYPASS: (
+        "Stop. Manual state/mtime/source-file bypass is forbidden. Use "
+        "sanctioned MCP tools only; never delete or rewrite session-state "
+        "or lock files by hand."
+    ),
+}
+
+
+def is_mutation_task(task: str | None) -> bool:
+    """True when *task* is in the #604 mutation set (normalized)."""
+    name = (task or "").strip().lower().removeprefix("gitea_")
+    if not name:
+        return False
+    if name in MUTATION_TASKS:
+        return True
+    # Accept gitea_ prefixed membership for aliases already in the set.
+    return f"gitea_{name}" in MUTATION_TASKS
+
+
+def roles_compatible(active_role: str | None, required_role: str | None) -> bool:
+    """Whether *active_role* may perform a task that maps to *required_role*.
+
+    Exact match always passes. Reconcilers may run author-class mutations
+    (comment/close/cleanup) that the capability map stamps as ``author`` —
+    matching the long-standing reconciler exemption for control-checkout
+    work. No other cross-role substitutions are allowed.
+
+    Capability-authorized multi-role tasks (e.g. reviewer holding
+    ``gitea.issue.comment`` for ``comment_issue``) are handled by
+    :func:`authorization_compatible`, not by expanding this role matrix.
+    """
+    active = (active_role or "").strip().lower()
+    required = (required_role or "").strip().lower()
+    if not active or not required:
+        return True
+    if active == required:
+        return True
+    if active == "reconciler" and required in {"author", "reconciler"}:
+        return True
+    return False
+
+
+def authorization_compatible(
+    active_role: str | None,
+    required_role: str | None,
+    *,
+    required_permission: str | None = None,
+    allowed_operations: Any = None,
+) -> bool:
+    """Whether the active session may run a task given role *and* capability.
+
+    Order:
+
+    1. :func:`roles_compatible` (exact role or narrow reconciler→author).
+    2. Capability possession: when *required_permission* is non-empty and
+       present in *allowed_operations*, allow even if the nominal task role
+       differs (e.g. reviewer/merger with ``gitea.issue.comment`` on
+       ``comment_issue`` / ``mark_issue`` / ``set_issue_labels`` /
+       ``lock_issue``).
+
+    Fail closed otherwise. This is **not** a broad reviewer→author or
+    merger→author role rewrite: without the specific permission the check
+    still denies. Missing *allowed_operations* when a permission is required
+    also fails closed (callers must supply the live profile op list).
+    """
+    if roles_compatible(active_role, required_role):
+        return True
+    perm = (required_permission or "").strip()
+    if not perm:
+        return False
+    if allowed_operations is None:
+        return False
+    try:
+        ops = {str(o).strip() for o in allowed_operations if o is not None}
+    except TypeError:
+        return False
+    return perm in ops
+
+
+def _blocker(
+    kind: str,
+    reasons: list[str],
+    *,
+    exact_next_action: str | None = None,
+    detail: dict | None = None,
+) -> dict[str, Any]:
+    if kind not in BLOCKER_KINDS:
+        raise ValueError(f"unknown anti-stomp blocker kind: {kind!r}")
+    return {
+        "kind": kind,
+        "reasons": list(reasons),
+        "exact_next_action": exact_next_action or _NEXT_ACTIONS[kind],
+        "detail": dict(detail or {}),
+    }
+
+
+def _allowed_result(checks: dict[str, Any]) -> dict[str, Any]:
+    return {
+        "allowed": True,
+        "block": False,
+        "blockers": [],
+        "reasons": [],
+        "exact_next_action": "proceed",
+        "blocker_kind": None,
+        "checks": checks,
+    }
+
+
+def _blocked_result(
+    blockers: list[dict[str, Any]],
+    checks: dict[str, Any],
+) -> dict[str, Any]:
+    primary = blockers[0]
+    all_reasons: list[str] = []
+    for b in blockers:
+        for r in b.get("reasons") or []:
+            if r not in all_reasons:
+                all_reasons.append(r)
+    return {
+        "allowed": False,
+        "block": True,
+        "blockers": blockers,
+        "reasons": all_reasons,
+        "exact_next_action": primary["exact_next_action"],
+        "blocker_kind": primary["kind"],
+        "checks": checks,
+    }
+
+
+def assess_anti_stomp_preflight(
+    *,
+    task: str | None = None,
+    # repo/org
+    remote: str | None = None,
+    resolved_org: str | None = None,
+    resolved_repo: str | None = None,
+    local_remote_url: str | None = None,
+    org_explicit: bool = False,
+    repo_explicit: bool = False,
+    check_repo: bool = True,
+    # profile/role + capability
+    profile_name: str | None = None,
+    profile_role: str | None = None,
+    required_role: str | None = None,
+    required_permission: str | None = None,
+    allowed_operations: Any = None,
+    check_role: bool = True,
+    # root checkout + worktree
+    workspace_path: str | None = None,
+    project_root: str | None = None,
+    current_branch: str | None = None,
+    root_head_sha: str | None = None,
+    root_porcelain: str | None = None,
+    remote_master_sha: str | None = None,
+    check_root_checkout: bool = True,
+    check_worktree: bool = True,
+    # stale runtime (master parity)
+    startup_head: str | None = None,
+    current_code_head: str | None = None,
+    check_stale_runtime: bool = True,
+    # lease ownership
+    lease_required: bool = False,
+    foreign_lease: bool | None = None,
+    lease_owner_session: str | None = None,
+    active_session_id: str | None = None,
+    lease_owner_identity: str | None = None,
+    active_identity: str | None = None,
+    lease_reasons: list[str] | None = None,
+    # terminal lock
+    terminal_lock_blocks: bool | None = None,
+    terminal_lock_reasons: list[str] | None = None,
+    # expected head SHA
+    require_head_sha: bool = False,
+    expected_head_sha: str | None = None,
+    live_head_sha: str | None = None,
+    # workflow hash
+    workflow_hash_valid: bool | None = None,
+    workflow_hash_reasons: list[str] | None = None,
+    # source contamination (stable-branch push / approval contamination)
+    source_contaminated: bool | None = None,
+    contamination_reasons: list[str] | None = None,
+    # manual bypass
+    manual_bypass_attempted: bool = False,
+    manual_bypass_reasons: list[str] | None = None,
+) -> dict[str, Any]:
+    """Fail-closed common anti-stomp assessment (pure).
+
+    Only checks for which facts are supplied (or which are required by the
+    mutation category) are evaluated. Unsupplied optional facts are recorded
+    as ``skipped`` so callers can see coverage without inventing defaults.
+
+    Returns a structured dict with ``allowed``/``block``, typed ``blockers``,
+    aggregated ``reasons``, ``exact_next_action``, and per-check ``checks``.
+    """
+    task_name = (task or "").strip()
+    role = (profile_role or "").strip().lower() or None
+    req_role = (required_role or "").strip().lower() or None
+    req_perm = (required_permission or "").strip() or None
+    checks: dict[str, Any] = {
+        "task": task_name or None,
+        "profile_name": profile_name,
+        "profile_role": role,
+        "required_role": req_role,
+        "required_permission": req_perm,
+    }
+    blockers: list[dict[str, Any]] = []
+
+    # ── manual bypass (always first; never skippable when attempted) ─────────
+    if manual_bypass_attempted:
+        reasons = list(manual_bypass_reasons or [
+            "manual state/mtime/source-file bypass attempt detected (fail closed)"
+        ])
+        blockers.append(_blocker(BLOCKER_MANUAL_BYPASS, reasons))
+        checks["manual_bypass"] = {"block": True, "reasons": reasons}
+    else:
+        checks["manual_bypass"] = {"block": False, "skipped": False}
+
+    # ── repo/org ─────────────────────────────────────────────────────────────
+    if check_repo and resolved_org is not None and resolved_repo is not None:
+        repo_assessment = remote_repo_guard.assess_remote_repo_match(
+            remote=remote or "",
+            resolved_org=resolved_org,
+            resolved_repo=resolved_repo,
+            local_remote_url=local_remote_url,
+            org_explicit=org_explicit,
+            repo_explicit=repo_explicit,
+        )
+        checks["repo"] = {
+            "block": bool(repo_assessment.get("block")),
+            "reasons": list(repo_assessment.get("reasons") or []),
+            "resolved_org": resolved_org,
+            "resolved_repo": resolved_repo,
+        }
+        if repo_assessment.get("block"):
+            blockers.append(
+                _blocker(
+                    BLOCKER_WRONG_REPO,
+                    list(repo_assessment.get("reasons") or ["repo/org mismatch"]),
+                    detail={
+                        "resolved_org": resolved_org,
+                        "resolved_repo": resolved_repo,
+                        "local_remote_url": local_remote_url,
+                    },
+                )
+            )
+    else:
+        checks["repo"] = {"block": False, "skipped": True}
+
+    # ── profile/role + capability ────────────────────────────────────────────
+    # Role match OR possession of the task's required permission (Blocker A).
+    # Reviewer/merger may run issue-comment-class tasks when they hold
+    # gitea.issue.comment; unauthorized escalation without the permission
+    # still fails closed.
+    if check_role and req_role and role:
+        authorized = authorization_compatible(
+            role,
+            req_role,
+            required_permission=req_perm,
+            allowed_operations=allowed_operations,
+        )
+        if not authorized:
+            perm_clause = (
+                f", required_permission='{req_perm}'" if req_perm else ""
+            )
+            reasons = [
+                f"active profile role '{role}' is not authorized for task "
+                f"'{task_name or '(unknown)'}' (required_role='{req_role}'"
+                f"{perm_clause}; profile={profile_name or '(unknown)'})"
+            ]
+            checks["role"] = {
+                "block": True,
+                "reasons": reasons,
+                "required_permission": req_perm,
+                "capability_authorized": False,
+            }
+            blockers.append(
+                _blocker(
+                    BLOCKER_WRONG_ROLE,
+                    reasons,
+                    detail={
+                        "profile_name": profile_name,
+                        "profile_role": role,
+                        "required_role": req_role,
+                        "required_permission": req_perm,
+                    },
+                )
+            )
+        else:
+            checks["role"] = {
+                "block": False,
+                "reasons": [],
+                "required_permission": req_perm,
+                "capability_authorized": bool(
+                    req_perm
+                    and allowed_operations is not None
+                    and req_perm in {
+                        str(o).strip() for o in (allowed_operations or [])
+                        if o is not None
+                    }
+                    and not roles_compatible(role, req_role)
+                ),
+            }
+    else:
+        checks["role"] = {"block": False, "skipped": True}
+
+    # ── stale runtime (master parity) ────────────────────────────────────────
+    if check_stale_runtime and (
+        startup_head is not None or current_code_head is not None
+    ):
+        parity = master_parity_gate.assess_master_parity(
+            {"startup_head": startup_head},
+            current_code_head,
+        )
+        stale_reasons = master_parity_gate.parity_block_reasons(parity)
+        checks["stale_runtime"] = {
+            "block": bool(stale_reasons),
+            "reasons": list(stale_reasons),
+            "startup_head": startup_head,
+            "current_code_head": current_code_head,
+            "stale": bool(parity.get("stale")),
+        }
+        if stale_reasons:
+            blockers.append(
+                _blocker(
+                    BLOCKER_STALE_RUNTIME,
+                    list(stale_reasons),
+                    detail={
+                        "startup_head": startup_head,
+                        "current_code_head": current_code_head,
+                    },
+                )
+            )
+    else:
+        checks["stale_runtime"] = {"block": False, "skipped": True}
+
+    # ── root checkout ────────────────────────────────────────────────────────
+    if (
+        check_root_checkout
+        and workspace_path is not None
+        and project_root is not None
+        and root_porcelain is not None
+    ):
+        root_assessment = root_checkout_guard.assess_root_checkout_guard(
+            workspace_path=workspace_path,
+            canonical_repo_root=project_root,
+            current_branch=current_branch,
+            head_sha=root_head_sha,
+            porcelain_status=root_porcelain,
+            remote_master_sha=remote_master_sha,
+            resolved_role=req_role or role,
+            actual_role=role,
+        )
+        checks["root_checkout"] = {
+            "block": bool(root_assessment.get("block")),
+            "reasons": list(root_assessment.get("reasons") or []),
+        }
+        if root_assessment.get("block"):
+            blockers.append(
+                _blocker(
+                    BLOCKER_ROOT_CHECKOUT,
+                    list(root_assessment.get("reasons") or [
+                        "control checkout is not clean master"
+                    ]),
+                    detail={
+                        "workspace_path": workspace_path,
+                        "project_root": project_root,
+                        "current_branch": current_branch,
+                    },
+                )
+            )
+    else:
+        checks["root_checkout"] = {"block": False, "skipped": True}
+
+    # ── worktree under branches (author) ─────────────────────────────────────
+    worktree_role = role or req_role
+    if (
+        check_worktree
+        and workspace_path is not None
+        and project_root is not None
+        and worktree_role in _BRANCHES_REQUIRED_ROLES
+    ):
+        wt = author_mutation_worktree.assess_author_mutation_worktree(
+            workspace_path=workspace_path,
+            project_root=project_root,
+            current_branch=current_branch,
+        )
+        checks["worktree"] = {
+            "block": bool(wt.get("block")),
+            "reasons": list(wt.get("reasons") or []),
+            "under_branches": wt.get("under_branches"),
+        }
+        if wt.get("block"):
+            blockers.append(
+                _blocker(
+                    BLOCKER_WRONG_WORKTREE,
+                    list(wt.get("reasons") or [
+                        "mutation worktree is not under branches/"
+                    ]),
+                    detail={
+                        "workspace_path": workspace_path,
+                        "project_root": project_root,
+                    },
+                )
+            )
+    else:
+        checks["worktree"] = {
+            "block": False,
+            "skipped": worktree_role not in _BRANCHES_REQUIRED_ROLES
+            or workspace_path is None,
+        }
+
+    # ── foreign lease ────────────────────────────────────────────────────────
+    lease_needed = lease_required or (
+        task_name.removeprefix("gitea_") in {
+            t.removeprefix("gitea_") for t in _LEASE_AWARE_TASKS
+        }
+        and foreign_lease is not None
+    )
+    if lease_needed or foreign_lease is True:
+        is_foreign = bool(foreign_lease)
+        if foreign_lease is None and lease_required:
+            # Ownership must be proven when lease_required; missing ownership
+            # facts fail closed.
+            owner_ok = (
+                (not lease_owner_session and not active_session_id)
+                or (
+                    lease_owner_session
+                    and active_session_id
+                    and lease_owner_session == active_session_id
+                )
+            )
+            identity_ok = (
+                (not lease_owner_identity and not active_identity)
+                or (
+                    lease_owner_identity
+                    and active_identity
+                    and lease_owner_identity == active_identity
+                )
+            )
+            if not owner_ok or not identity_ok:
+                is_foreign = True
+        reasons = list(lease_reasons or [])
+        if is_foreign and not reasons:
+            reasons = [
+                "active lease is owned by a foreign session or identity "
+                "(anti-stomp fail closed)"
+            ]
+        checks["lease"] = {
+            "block": is_foreign,
+            "reasons": reasons if is_foreign else [],
+            "lease_owner_session": lease_owner_session,
+            "active_session_id": active_session_id,
+        }
+        if is_foreign:
+            blockers.append(
+                _blocker(BLOCKER_FOREIGN_LEASE, reasons)
+            )
+    else:
+        checks["lease"] = {"block": False, "skipped": True}
+
+    # ── terminal lock ────────────────────────────────────────────────────────
+    if terminal_lock_blocks is not None:
+        reasons = list(terminal_lock_reasons or [])
+        if terminal_lock_blocks and not reasons:
+            reasons = [
+                "terminal review-decision lock is active for this head "
+                "(anti-stomp fail closed)"
+            ]
+        checks["terminal_lock"] = {
+            "block": bool(terminal_lock_blocks),
+            "reasons": reasons if terminal_lock_blocks else [],
+        }
+        if terminal_lock_blocks:
+            blockers.append(_blocker(BLOCKER_TERMINAL_LOCK, reasons))
+    else:
+        checks["terminal_lock"] = {"block": False, "skipped": True}
+
+    # ── expected head SHA ────────────────────────────────────────────────────
+    if require_head_sha or (
+        expected_head_sha is not None and live_head_sha is not None
+    ):
+        exp = (expected_head_sha or "").strip().lower()
+        live = (live_head_sha or "").strip().lower()
+        mismatch = False
+        reasons: list[str] = []
+        if require_head_sha and not exp:
+            mismatch = True
+            reasons.append(
+                "expected_head_sha is required before this mutation "
+                "(anti-stomp fail closed)"
+            )
+        elif exp and live and exp != live:
+            mismatch = True
+            reasons.append(
+                f"expected_head_sha '{exp}' does not match live PR head "
+                f"'{live}' (anti-stomp fail closed; stale prompt data)"
+            )
+        elif require_head_sha and exp and not live:
+            mismatch = True
+            reasons.append(
+                "live PR head SHA could not be determined to corroborate "
+                "expected_head_sha (anti-stomp fail closed)"
+            )
+        checks["head_sha"] = {
+            "block": mismatch,
+            "reasons": reasons,
+            "expected_head_sha": expected_head_sha,
+            "live_head_sha": live_head_sha,
+        }
+        if mismatch:
+            blockers.append(_blocker(BLOCKER_HEAD_SHA, reasons))
+    else:
+        checks["head_sha"] = {"block": False, "skipped": True}
+
+    # ── workflow hash ────────────────────────────────────────────────────────
+    if workflow_hash_valid is not None:
+        reasons = list(workflow_hash_reasons or [])
+        if not workflow_hash_valid and not reasons:
+            reasons = [
+                "workflow load proof missing or hash stale "
+                "(anti-stomp fail closed)"
+            ]
+        checks["workflow_hash"] = {
+            "block": not bool(workflow_hash_valid),
+            "reasons": reasons if not workflow_hash_valid else [],
+        }
+        if not workflow_hash_valid:
+            blockers.append(_blocker(BLOCKER_WORKFLOW_HASH, reasons))
+    else:
+        checks["workflow_hash"] = {"block": False, "skipped": True}
+
+    # ── source contamination ─────────────────────────────────────────────────
+    if source_contaminated is not None:
+        reasons = list(contamination_reasons or [])
+        if source_contaminated and not reasons:
+            reasons = [
+                "session is source-contaminated (stable-branch push or "
+                "contaminated approval path); anti-stomp fail closed"
+            ]
+        checks["source_contamination"] = {
+            "block": bool(source_contaminated),
+            "reasons": reasons if source_contaminated else [],
+        }
+        if source_contaminated:
+            blockers.append(
+                _blocker(BLOCKER_SOURCE_CONTAMINATION, reasons)
+            )
+    else:
+        checks["source_contamination"] = {"block": False, "skipped": True}
+
+    if blockers:
+        return _blocked_result(blockers, checks)
+    return _allowed_result(checks)
+
+
+def format_anti_stomp_error(assessment: dict[str, Any]) -> str:
+    """Single RuntimeError message for MCP mutation gates."""
+    kind = assessment.get("blocker_kind") or "unknown"
+    reasons = "; ".join(
+        assessment.get("reasons")
+        or ["anti-stomp preflight blocked the mutation"]
+    )
+    next_action = assessment.get("exact_next_action") or "stop and diagnose"
+    return (
+        f"Anti-stomp preflight (#604) blocked mutation "
+        f"[{kind}]: {reasons}. "
+        f"exact_next_action: {next_action}"
+    )
+
+
+def block_response(
+    assessment: dict[str, Any],
+    **extra_fields: Any,
+) -> dict[str, Any]:
+    """Structured tool-return payload for a blocked mutation."""
+    payload = {
+        "success": False,
+        "performed": False,
+        "blocked": True,
+        "anti_stomp": True,
+        "blocker_kind": assessment.get("blocker_kind"),
+        "blockers": list(assessment.get("blockers") or []),
+        "reasons": list(assessment.get("reasons") or []),
+        "exact_next_action": assessment.get("exact_next_action"),
+        "checks": assessment.get("checks") or {},
+    }
+    payload.update(extra_fields)
+    return payload
+
+
+def contamination_from_stable_marker(
+    marker: dict | None,
+    *,
+    task: str | None,
+    actual_role: str | None,
+) -> tuple[bool, list[str]]:
+    """Derive source-contamination facts from a #671 durable marker."""
+    if not marker:
+        return False, []
+    gate = stable_branch_push_guard.assess_contamination_gate(
+        marker,
+        task=task,
+        actual_role=actual_role,
+    )
+    if gate.get("block"):
+        return True, list(gate.get("reasons") or [])
+    return False, []

gitea_mcp_server.py

@@ -755,6 +755,188 @@ def _enforce_branches_only_author_mutation(worktree_path: str | None = None) ->
         )
 
 
+def _anti_stomp_in_test_mode() -> bool:
+    """Whether the #604 anti-stomp gate is skipped under pytest.
+
+    Mirrors remote-repo / stable-contamination test bypasses so the existing
+    suite (bare remotes, mocked APIs) stays green. Set
+    ``GITEA_TEST_FORCE_ANTI_STOMP=1`` to exercise the live gate under tests.
+    """
+    if not _preflight_in_test_mode():
+        return False
+    return not bool(os.environ.get("GITEA_TEST_FORCE_ANTI_STOMP"))
+
+
+def _run_anti_stomp_preflight(
+    task: str | None,
+    *,
+    remote: str | None = None,
+    worktree_path: str | None = None,
+    host: str | None = None,
+    org: str | None = None,
+    repo: str | None = None,
+    expected_head_sha: str | None = None,
+    live_head_sha: str | None = None,
+    require_head_sha: bool = False,
+    lease_required: bool = False,
+    foreign_lease: bool | None = None,
+    lease_reasons: list[str] | None = None,
+    terminal_lock_blocks: bool | None = None,
+    terminal_lock_reasons: list[str] | None = None,
+    workflow_hash_valid: bool | None = None,
+    workflow_hash_reasons: list[str] | None = None,
+    raise_on_block: bool = True,
+) -> dict | None:
+    """Shared #604 anti-stomp preflight for MCP mutation entrypoints.
+
+    Gathers live workspace/parity/role/repo facts and invokes the pure
+    :func:`anti_stomp_preflight.assess_anti_stomp_preflight` assessor. On
+    block, raises ``RuntimeError`` (default) or returns a structured
+    :func:`anti_stomp_preflight.block_response` when *raise_on_block* is
+    False. Returns ``None`` when the mutation may proceed.
+    """
+    if _anti_stomp_in_test_mode():
+        return None
+
+    # Only enforce when the caller names a known mutation task. Read-only
+    # paths and legacy verify_preflight_purity calls without a task stay
+    # on the pre-#604 gate chain (whoami/capability/root/worktree).
+    if not task or not anti_stomp_preflight.is_mutation_task(task):
+        return None
+
+    profile = get_profile()
+    profile_name = profile.get("profile_name")
+    profile_role = _actual_profile_role()
+    allowed_operations = list(profile.get("allowed_operations") or [])
+    req_role = None
+    req_perm = None
+    if task:
+        try:
+            req_role = task_capability_map.required_role(task)
+        except KeyError:
+            req_role = _preflight_resolved_role
+        try:
+            req_perm = task_capability_map.required_permission(task)
+        except KeyError:
+            req_perm = None
+
+    ctx = _resolve_namespace_mutation_context(worktree_path)
+    workspace = ctx["workspace_path"]
+    canonical_root = ctx["canonical_repo_root"]
+    git_state = issue_lock_worktree.read_worktree_git_state(canonical_root)
+    remote_master_sha = root_checkout_guard.resolve_remote_master_sha(canonical_root)
+
+    # Repo/org facts (best-effort; explicit org/repo when provided).
+    resolved_org = org
+    resolved_repo = repo
+    local_remote_url = None
+    org_explicit = org is not None
+    repo_explicit = repo is not None
+    if remote:
+        try:
+            local_remote_url = _local_git_remote_url(remote)
+        except Exception:
+            local_remote_url = None
+        if resolved_org is None or resolved_repo is None:
+            try:
+                rem = _effective_remote(remote)
+                if rem in REMOTES:
+                    if resolved_org is None:
+                        resolved_org = REMOTES[rem]["org"]
+                    if resolved_repo is None:
+                        resolved_repo = REMOTES[rem]["repo"]
+            except Exception:
+                pass
+
+    parity = _current_master_parity()
+    startup_head = parity.get("startup_head")
+    current_code_head = parity.get("current_head")
+
+    # Source contamination from durable #671 marker (role-aware).
+    source_contaminated = None
+    contamination_reasons = None
+    try:
+        marker = _load_stable_contamination_marker(remote)
+        contaminated, cont_reasons = anti_stomp_preflight.contamination_from_stable_marker(
+            marker,
+            task=task,
+            actual_role=profile_role,
+        )
+        if marker is not None:
+            source_contaminated = contaminated
+            contamination_reasons = cont_reasons
+    except Exception:
+        # Fail soft on marker I/O: existing #671 enforcer still runs separately.
+        source_contaminated = None
+
+    # Workflow-hash facts when the task is review/merge oriented.
+    if workflow_hash_valid is None and task in {
+        "review_pr",
+        "submit_pr_review",
+        "approve_pr",
+        "request_changes_pr",
+        "merge_pr",
+    }:
+        try:
+            wf_reasons = _review_workflow_load_gate_reasons()
+            workflow_hash_valid = not bool(wf_reasons)
+            workflow_hash_reasons = list(wf_reasons) if wf_reasons else None
+        except Exception:
+            pass
+
+    # Mirror remote_repo_guard's pytest bypass: under the unit suite bare
+    # remote=prgs still defaults to Timesheet, and re-checking here would
+    # break happy-path reconciler/author tests that already rely on the
+    # #530 gate being opt-in via GITEA_FORCE_REMOTE_REPO_CHECK.
+    check_repo = True
+    if "pytest" in sys.modules and not os.environ.get(
+        "GITEA_FORCE_REMOTE_REPO_CHECK"
+    ):
+        check_repo = False
+
+    assessment = anti_stomp_preflight.assess_anti_stomp_preflight(
+        task=task,
+        remote=remote,
+        resolved_org=resolved_org,
+        resolved_repo=resolved_repo,
+        local_remote_url=local_remote_url,
+        org_explicit=org_explicit,
+        repo_explicit=repo_explicit,
+        check_repo=check_repo,
+        profile_name=profile_name,
+        profile_role=profile_role,
+        required_role=req_role or _preflight_resolved_role,
+        required_permission=req_perm,
+        allowed_operations=allowed_operations,
+        workspace_path=workspace,
+        project_root=canonical_root,
+        current_branch=git_state.get("current_branch"),
+        root_head_sha=git_state.get("head_sha"),
+        root_porcelain=git_state.get("porcelain_status") or "",
+        remote_master_sha=remote_master_sha,
+        startup_head=startup_head,
+        current_code_head=current_code_head,
+        lease_required=lease_required,
+        foreign_lease=foreign_lease,
+        lease_reasons=lease_reasons,
+        terminal_lock_blocks=terminal_lock_blocks,
+        terminal_lock_reasons=terminal_lock_reasons,
+        require_head_sha=require_head_sha,
+        expected_head_sha=expected_head_sha,
+        live_head_sha=live_head_sha,
+        workflow_hash_valid=workflow_hash_valid,
+        workflow_hash_reasons=workflow_hash_reasons,
+        source_contaminated=source_contaminated,
+        contamination_reasons=contamination_reasons,
+        manual_bypass_attempted=False,
+    )
+    if not assessment.get("block"):
+        return None
+    if raise_on_block:
+        raise RuntimeError(anti_stomp_preflight.format_anti_stomp_error(assessment))
+    return anti_stomp_preflight.block_response(assessment)
+
+
 def verify_preflight_purity(
     remote: str | None = None,
     worktree_path: str | None = None,
@@ -762,13 +944,29 @@ def verify_preflight_purity(
     *,
     target_issue_number: int | None = None,
     require_author_lock: bool = False,
+    expected_head_sha: str | None = None,
+    live_head_sha: str | None = None,
+    require_head_sha: bool = False,
+    lease_required: bool = False,
+    foreign_lease: bool | None = None,
+    lease_reasons: list[str] | None = None,
+    terminal_lock_blocks: bool | None = None,
+    terminal_lock_reasons: list[str] | None = None,
+    workflow_hash_valid: bool | None = None,
+    workflow_hash_reasons: list[str] | None = None,
+    org: str | None = None,
+    repo: str | None = None,
 ):
-    """Verify identity/capability order, then production workspace guards.
+    """Verify identity/capability order, production workspace guards, then anti-stomp.
 
     #683: pytest/unittest must not skip production root/branches/scope
     enforcement when force-on signals request production behavior. The
     early return below only skips *preflight-order* purity checks under
     pure unit-test isolation — never when production guards are active.
+
+    #604: also runs the shared anti-stomp preflight for mutation tasks (typed
+    blocker + exact next action). Extended lease/head/terminal facts may be
+    supplied by review/merge callers.
     """
     global _preflight_reviewer_violation_files
 
@@ -779,7 +977,12 @@ def verify_preflight_purity(
     # Pure unit-test isolation: skip purity-order unless legacy dirty/porcelain
     # force flags request the dirtiness path. #683 FORCE_PRODUCTION_GUARDS alone
     # runs production root/branches/scope without requiring whoami/capability.
-    skip_purity_order = in_test and not workflow_scope_guard.purity_order_forced()
+    force_anti_stomp = bool(os.environ.get("GITEA_TEST_FORCE_ANTI_STOMP"))
+    skip_purity_order = (
+        in_test
+        and not workflow_scope_guard.purity_order_forced()
+        and not force_anti_stomp
+    )
 
     if not skip_purity_order:
         if not _preflight_whoami_called:
@@ -874,6 +1077,25 @@ def verify_preflight_purity(
             target_issue_number=target_issue_number,
             require_author_lock=require_author_lock,
         )
+        # #604: common anti-stomp preflight after legacy + #683 enforcers.
+        _run_anti_stomp_preflight(
+            task,
+            remote=remote,
+            worktree_path=worktree_path,
+            org=org,
+            repo=repo,
+            expected_head_sha=expected_head_sha,
+            live_head_sha=live_head_sha,
+            require_head_sha=require_head_sha,
+            lease_required=lease_required,
+            foreign_lease=foreign_lease,
+            lease_reasons=lease_reasons,
+            terminal_lock_blocks=terminal_lock_blocks,
+            terminal_lock_reasons=terminal_lock_reasons,
+            workflow_hash_valid=workflow_hash_valid,
+            workflow_hash_reasons=workflow_hash_reasons,
+            raise_on_block=True,
+        )
         _clear_preflight_capability_state()
         return
 
@@ -888,6 +1110,25 @@ def verify_preflight_purity(
             target_issue_number=target_issue_number,
             require_author_lock=require_author_lock,
         )
+        if force_anti_stomp:
+            _run_anti_stomp_preflight(
+                task,
+                remote=remote,
+                worktree_path=worktree_path,
+                org=org,
+                repo=repo,
+                expected_head_sha=expected_head_sha,
+                live_head_sha=live_head_sha,
+                require_head_sha=require_head_sha,
+                lease_required=lease_required,
+                foreign_lease=foreign_lease,
+                lease_reasons=lease_reasons,
+                terminal_lock_blocks=terminal_lock_blocks,
+                terminal_lock_reasons=terminal_lock_reasons,
+                workflow_hash_valid=workflow_hash_valid,
+                workflow_hash_reasons=workflow_hash_reasons,
+                raise_on_block=True,
+            )
 
 
 def _session_issue_lock_snapshot(
@@ -1256,6 +1497,7 @@ import root_checkout_guard  # noqa: E402
 import workflow_scope_guard  # noqa: E402  # #683 production scope / force-on guards
 import stable_branch_push_guard  # noqa: E402
 import remote_repo_guard  # noqa: E402
+import anti_stomp_preflight  # noqa: E402
 import issue_claim_heartbeat  # noqa: E402
 import issue_work_duplicate_gate  # noqa: E402
 import issue_workflow_labels  # noqa: E402
@@ -3617,6 +3859,8 @@ def init_review_decision_lock(remote: str | None, task: str | None, force: bool
         "live_mutations": [],
         "correction_authorized": False,
         "correction_reason": None,
+        "correction_pr_number": None,
+        "correction_head_sha": None,
     })
 
 
@@ -3712,21 +3956,30 @@ def check_review_decision_gate(
     if stale_review_decision_lock.prior_live_mutations_block_boundary(
         lock, pr_number=pr_number, expected_head_sha=ready_head
     ):
-        if prior and not lock.get("correction_authorized"):
+        scoped = stale_review_decision_lock.correction_applies(
+            lock, pr_number=pr_number, expected_head_sha=ready_head
+        )
+        if prior and not scoped:
             reasons.append(
                 "live review mutation already recorded for this PR head in this "
                 "run; only one live review mutation is allowed per head unless "
-                "gitea_authorize_review_correction was invoked (fail closed, #620)"
+                "gitea_authorize_review_correction was invoked for this same "
+                "PR/head (fail closed, #620/#693)"
             )
         elif (
             action in _TERMINAL_REVIEW_ACTIONS
-            and any(m.get("action") in _TERMINAL_REVIEW_ACTIONS for m in prior)
+            and any(
-            and not lock.get("correction_authorized")
+                isinstance(m, dict)
+                and m.get("action") in _TERMINAL_REVIEW_ACTIONS
+                and m.get("pr_number") == pr_number
+                for m in prior
+            )
+            and not scoped
         ):
             reasons.append(
                 "terminal review decision already submitted for this PR head in "
                 "this run; blocked unless an operator-approved correction was "
-                "authorized (fail closed, #620)"
+                "authorized for this same PR/head (fail closed, #620/#693)"
             )
 
     return reasons
@@ -3755,6 +4008,8 @@ def record_live_review_mutation(pr_number: int, action: str, review_id: int | No
     if lock.get("correction_authorized"):
         lock["correction_authorized"] = False
         lock["correction_reason"] = None
+        lock["correction_pr_number"] = None
+        lock["correction_head_sha"] = None
     _save_review_decision_lock(lock)
 
 
@@ -3798,11 +4053,13 @@ def terminal_review_hard_stop_reasons(
         and last.get("pr_number") == pr_number
     ):
         return []
-    if operation in ("mark_ready", "review", "resume") and lock.get(
+    if operation in ("mark_ready", "review", "resume") and (
-        "correction_authorized"
+        stale_review_decision_lock.correction_applies(
+            lock, pr_number=pr_number, expected_head_sha=expected_head_sha
+        )
     ):
         return []
-    # #620: same PR, different reviewed head → fresh decision boundary.
+    # #620 same-PR new head + #693 cross-PR isolation.
     if stale_review_decision_lock.terminal_boundary_allows_fresh_decision(
         lock,
         pr_number=pr_number,
@@ -3824,16 +4081,20 @@ def terminal_review_hard_stop_reasons(
         else ""
     )
     recovery = (
-        "if that PR is already merged/closed, use "
+        "exact_next_action: if that PR is already merged/closed, use "
-        "gitea_cleanup_stale_review_decision_lock (apply=true) after live-state "
+        "gitea_cleanup_stale_review_decision_lock(apply=true) after live-state "
-        "proof (#594); if the PR is still open but the head moved, mark/submit "
+        "proof (#594); if the same PR head moved, mark/submit with the new "
-        "with the new expected_head_sha (#620); never delete session-state "
+        "expected_head_sha (#620); if the target is a different PR, "
-        "files by hand"
+        "gitea_diagnose_review_decision_lock then mark_final on the target "
+        "(cross-PR isolation, #693); if same-head verdict was mistaken, "
+        "gitea_authorize_review_correction with matching target_pr_number "
+        "(not a generic unlock); never delete session-state files by hand; "
+        "if still blocked create/update a durable Gitea issue and stop"
     )
     return [
         "terminal review mutation already consumed in this run "
         f"({last.get('action')} on PR #{last.get('pr_number')}{head_note}); "
-        f"{guidance} (fail closed, #332); {recovery}"
+        f"{guidance} (fail closed, #332/#693); {recovery}"
     ]
 
 
@@ -4393,6 +4654,30 @@ def _evaluate_pr_review_submission(
         result["pr_work_lease"] = lease_block
         return result
 
+    if live:
+        # #604: common anti-stomp with live head + lease proof (typed blocker).
+        anti_task = {
+            "approve": "approve_pr",
+            "request_changes": "request_changes_pr",
+            "comment": "submit_pr_review",
+        }.get(action, "submit_pr_review")
+        try:
+            _run_anti_stomp_preflight(
+                anti_task,
+                remote=remote,
+                worktree_path=worktree_path,
+                org=org,
+                repo=repo,
+                expected_head_sha=pinned_sha,
+                live_head_sha=actual_sha,
+                require_head_sha=True,
+                foreign_lease=False,
+                terminal_lock_blocks=False,
+            )
+        except RuntimeError as exc:
+            reasons.append(str(exc))
+            return result
+
     if (body or "").strip():
         gate = _canonical_comment_gate(body, context="pr_review")
         if gate["blocked"]:
@@ -4498,10 +4783,33 @@ def gitea_mark_final_review_decision(
             "reasons": [
                 "review decision lock missing; resolve review_pr capability first"
             ],
+            "exact_next_action": (
+                "gitea_resolve_task_capability(task='review_pr') then retry "
+                "mark_final"
+            ),
+            "durable_issue_handoff": {
+                "required": True,
+                "instruction": (
+                    "If the lock cannot be seeded, create/update a durable "
+                    "Gitea issue and stop (#693 AC8)"
+                ),
+            },
         }
     session_reasons = _review_decision_session_reasons(lock)
     if session_reasons:
-        return {"marked_ready": False, "reasons": session_reasons}
+        classification = stale_review_decision_lock.classify_review_decision_lock(
+            lock,
+            target_pr_number=pr_number,
+            target_head_sha=expected_head_sha,
+            session_blockers=session_reasons,
+        )
+        fail = stale_review_decision_lock.build_precise_mark_final_failure(
+            classification
+        )
+        return {
+            "marked_ready": False,
+            **fail,
+        }
     if remote != lock.get("remote"):
         return {
             "marked_ready": False,
@@ -4509,6 +4817,7 @@ def gitea_mark_final_review_decision(
                 f"requested remote '{remote}' does not match locked remote "
                 f"'{lock.get('remote')}' (fail closed)"
             ],
+            "exact_next_action": "use the remote bound on the decision lock",
         }
     try:
         _, resolved_org, resolved_repo = _resolve(remote, None, org, repo)
@@ -4543,7 +4852,26 @@ def gitea_mark_final_review_decision(
         pr_number, "mark_ready", expected_head_sha=expected_head_sha
     )
     if hard_stop:
-        return {"marked_ready": False, "reasons": hard_stop}
+        classification = stale_review_decision_lock.classify_review_decision_lock(
+            lock,
+            target_pr_number=pr_number,
+            target_head_sha=expected_head_sha,
+            active_profile_identity=_decision_lock_binding().get(
+                "profile_identity"
+            ),
+        )
+        fail = stale_review_decision_lock.build_precise_mark_final_failure(
+            classification
+        )
+        # Prefer classification next_action when more precise; keep hard_stop
+        # text as primary reasons for operators.
+        return {
+            "marked_ready": False,
+            "reasons": hard_stop + list(fail.get("reasons") or []),
+            "classification": fail.get("classification"),
+            "exact_next_action": fail.get("exact_next_action"),
+            "durable_issue_handoff": fail.get("durable_issue_handoff"),
+        }
     if action not in _REVIEW_ACTIONS:
         return {
             "marked_ready": False,
@@ -4559,17 +4887,63 @@ def gitea_mark_final_review_decision(
                 "expected_head_sha required before marking final review "
                 "decision (fail closed, #399)"
             ],
+            "exact_next_action": "retry mark_final with expected_head_sha pin",
+        }
+    # Safe idempotency: already ready for same PR/action/head (#693 AC4).
+    ready_head = stale_review_decision_lock.normalize_head_sha(
+        lock.get("ready_expected_head_sha")
+    )
+    target_head = stale_review_decision_lock.normalize_head_sha(expected_head_sha)
+    if (
+        lock.get("final_review_decision_ready")
+        and lock.get("ready_pr_number") == pr_number
+        and lock.get("ready_action") == action
+        and ready_head
+        and target_head
+        and stale_review_decision_lock.heads_equal(ready_head, target_head)
+        and lock.get("ready_remote") == remote
+        and lock.get("ready_org") == org
+        and lock.get("ready_repo") == repo
+    ):
+        return {
+            "marked_ready": True,
+            "idempotent": True,
+            "pr_number": pr_number,
+            "action": action,
+            "expected_head_sha": expected_head_sha,
+            "remote": remote,
+            "org": org,
+            "repo": repo,
+            "final_review_decision_ready": True,
+            "head_scoped": True,
+            "reasons": [
+                "final review decision already marked ready for this PR/action/"
+                "head (idempotent, #693)"
+            ],
         }
     if stale_review_decision_lock.prior_live_mutations_block_boundary(
         lock, pr_number=pr_number, expected_head_sha=expected_head_sha
     ):
+        classification = stale_review_decision_lock.classify_review_decision_lock(
+            lock,
+            target_pr_number=pr_number,
+            target_head_sha=expected_head_sha,
+        )
+        fail = stale_review_decision_lock.build_precise_mark_final_failure(
+            classification
+        )
         return {
             "marked_ready": False,
             "reasons": [
                 "cannot mark final decision after a live review mutation was "
                 "already recorded for this PR head unless an operator-approved "
-                "correction was authorized (fail closed, #620)"
+                "correction was authorized for this same PR/head "
-            ],
+                "(fail closed, #620/#693)"
+            ]
+            + list(fail.get("reasons") or []),
+            "classification": fail.get("classification"),
+            "exact_next_action": fail.get("exact_next_action"),
+            "durable_issue_handoff": fail.get("durable_issue_handoff"),
         }
     elig = gitea_check_pr_eligibility(
         pr_number=pr_number,
@@ -4653,8 +5027,19 @@ def gitea_authorize_review_correction(
     prior_review_state: str,
     reason: str,
     operator_authorized: bool = False,
+    target_pr_number: int | None = None,
+    expected_head_sha: str | None = None,
+    remote: str = "dadeschools",
+    org: str | None = None,
+    repo: str | None = None,
+    post_audit_comment: bool = True,
 ) -> dict:
-    """Authorize one operator-approved correction after a mistaken live review."""
+    """Authorize one operator-approved correction after a mistaken live review.
+
+    #693: correction is scoped to the named prior review's **PR and head**.
+    It cannot unlock a different PR (no generic decision-lock bypass).
+    Successful authorization posts a thread-visible audit on the target PR.
+    """
     reason = (reason or "").strip()
     prior_review_state = (prior_review_state or "").strip().lower()
     lock = _load_review_decision_lock()
@@ -4680,7 +5065,20 @@ def gitea_authorize_review_correction(
     last_mutation = prior[-1]
     last_review_id = last_mutation.get("review_id")
     last_review_state = last_mutation.get("action")
+    last_pr = last_mutation.get("pr_number")
+    last_head = stale_review_decision_lock.mutation_head_sha(last_mutation, lock)
     reasons = []
+    if target_pr_number is None:
+        reasons.append(
+            "target_pr_number is required so correction cannot become a "
+            "generic unlock (fail closed, #693)"
+        )
+    elif last_pr is not None and int(target_pr_number) != int(last_pr):
+        reasons.append(
+            f"target_pr_number #{target_pr_number} does not match last "
+            f"recorded mutation PR #{last_pr}; correction cannot unlock a "
+            f"different PR (fail closed, #693)"
+        )
     if last_review_id is not None and last_review_id != prior_review_id:
         reasons.append(
             f"prior review ID '{prior_review_id}' does not match last "
@@ -4691,14 +5089,202 @@ def gitea_authorize_review_correction(
             f"prior review state '{prior_review_state}' does not match last "
             f"recorded review state '{last_review_state}' (fail closed)"
         )
+    want_head = stale_review_decision_lock.normalize_head_sha(expected_head_sha)
+    if want_head and last_head and not stale_review_decision_lock.heads_equal(
+        want_head, last_head
+    ):
+        reasons.append(
+            f"expected_head_sha does not match last mutation head "
+            f"{last_head[:12]}… (fail closed, #693)"
+        )
     if not reason:
         reasons.append("correction reason is required")
+    try:
+        actor = None
+        h, o, r = _resolve(remote, None, org, repo)
+        try:
+            actor = _authenticated_username(h)
+        except Exception:
+            actor = None
+    except Exception as exc:  # noqa: BLE001
+        return {
+            "authorized": False,
+            "reasons": [f"could not resolve remote for audit: {_redact(str(exc))}"],
+        }
+    profile = get_profile()
+    profile_name = (profile.get("profile_name") or "").strip() or None
+    audit = stale_review_decision_lock.build_correction_audit_record(
+        prior_review_id=prior_review_id,
+        prior_review_state=prior_review_state,
+        target_pr_number=target_pr_number if target_pr_number is not None else last_pr,
+        target_head_sha=want_head or last_head,
+        reason=reason,
+        actor_username=actor,
+        profile_name=profile_name,
+        authorized=False,
+    )
     if reasons:
-        return {"authorized": False, "reasons": reasons}
+        return {
+            "authorized": False,
+            "reasons": reasons,
+            "audit": audit,
+            "exact_next_action": (
+                "use same-PR correction only, or for a different PR use "
+                "gitea_diagnose_review_decision_lock / cross-PR isolation "
+                "(#693) or moot cleanup (#594)"
+            ),
+        }
+    scope_pr = int(target_pr_number) if target_pr_number is not None else int(last_pr)
+    scope_head = want_head or last_head
     lock["correction_authorized"] = True
     lock["correction_reason"] = reason
+    lock["correction_pr_number"] = scope_pr
+    lock["correction_head_sha"] = scope_head
     _save_review_decision_lock(lock)
-    return {"authorized": True, "correction_reason": reason, "reasons": []}
+    audit = stale_review_decision_lock.build_correction_audit_record(
+        prior_review_id=prior_review_id,
+        prior_review_state=prior_review_state,
+        target_pr_number=scope_pr,
+        target_head_sha=scope_head,
+        reason=reason,
+        actor_username=actor,
+        profile_name=profile_name,
+        authorized=True,
+    )
+    report = {
+        "authorized": True,
+        "correction_reason": reason,
+        "correction_pr_number": scope_pr,
+        "correction_head_sha": scope_head,
+        "audit": audit,
+        "audit_comment_id": None,
+        "reasons": [],
+        "scope": "same_pr_head_only",
+    }
+    if post_audit_comment and scope_pr is not None:
+        comment_block = _profile_operation_gate("gitea.pr.comment")
+        if comment_block:
+            report["audit_comment_skipped"] = comment_block
+        else:
+            try:
+                auth = _auth(h)
+                body = stale_review_decision_lock.format_correction_audit_comment(
+                    audit
+                )
+                with _audited(
+                    "comment_pr",
+                    host=h,
+                    remote=remote,
+                    org=o,
+                    repo=r,
+                    pr_number=scope_pr,
+                    request_metadata={"source": "authorize_review_correction"},
+                ):
+                    posted = api_request(
+                        "POST",
+                        f"{repo_api_url(h, o, r)}/issues/{scope_pr}/comments",
+                        auth,
+                        {"body": body},
+                    )
+                report["audit_comment_id"] = (posted or {}).get("id")
+            except Exception as exc:  # noqa: BLE001
+                report["audit_comment_error"] = _redact(str(exc))
+    return report
+
+
+@mcp.tool()
+def gitea_diagnose_review_decision_lock(
+    target_pr_number: int,
+    expected_head_sha: str | None = None,
+    remote: str = "dadeschools",
+    host: str | None = None,
+    org: str | None = None,
+    repo: str | None = None,
+) -> dict:
+    """Read-only: classify durable review-decision lock state for a target PR (#693).
+
+    Returns a deterministic classification, owner/evidence, exact next_action,
+    and whether mark_final / cleanup / scoped correction are appropriate.
+    Never mutates the lock and never authorizes correction.
+    """
+    read_block = _profile_operation_gate("gitea.read")
+    if read_block:
+        return {
+            "success": False,
+            "reasons": read_block,
+            "permission_report": _permission_block_report("gitea.read"),
+        }
+    h, o, r = _resolve(remote, host, org, repo)
+    auth = _auth(h)
+    binding = _decision_lock_binding()
+    lock = _load_review_decision_lock()
+    session_blockers = _review_decision_session_reasons(lock) if lock else []
+    last = stale_review_decision_lock.last_terminal_mutation(lock)
+    pr_live = None
+    pr_lookup_error = None
+    last_pr = last.get("pr_number") if last else None
+    if last_pr is not None:
+        try:
+            pr_live = api_request(
+                "GET", f"{repo_api_url(h, o, r)}/pulls/{last_pr}", auth
+            ) or {}
+            if not pr_live:
+                pr_lookup_error = "empty PR payload"
+        except Exception as exc:  # noqa: BLE001
+            pr_lookup_error = _redact(str(exc))
+    classification = stale_review_decision_lock.classify_review_decision_lock(
+        lock,
+        target_pr_number=target_pr_number,
+        target_head_sha=expected_head_sha,
+        pr_live=pr_live,
+        pr_lookup_error=pr_lookup_error,
+        active_profile_identity=binding.get("profile_identity"),
+        session_blockers=session_blockers,
+    )
+    recovery = stale_review_decision_lock.assess_open_pr_decision_lock_recovery(
+        lock,
+        target_pr_number=target_pr_number,
+        target_head_sha=expected_head_sha,
+        last_terminal_pr_live=pr_live,
+        pr_lookup_error=pr_lookup_error,
+        active_profile_identity=binding.get("profile_identity"),
+        session_blockers=session_blockers,
+    )
+    try:
+        actor = _authenticated_username(h)
+    except Exception:
+        actor = None
+    return {
+        "success": True,
+        "remote": remote,
+        "org": o,
+        "repo": r,
+        "authenticated_username": actor,
+        "active_profile_identity": binding.get("profile_identity"),
+        "classification": classification.get("classification"),
+        "mark_final_allowed": classification.get("mark_final_allowed"),
+        "cleanup_allowed": classification.get("cleanup_allowed"),
+        "correction_eligible": classification.get("correction_eligible"),
+        "recovery_allowed": recovery.get("recovery_allowed"),
+        "recovery_mode": recovery.get("recovery_mode"),
+        "exact_next_action": classification.get("next_action"),
+        "owner_profile_identity": classification.get("owner_profile_identity"),
+        "last_terminal_pr": classification.get("last_terminal_pr"),
+        "last_terminal_action": classification.get("last_terminal_action"),
+        "locked_head_sha": classification.get("locked_head_sha"),
+        "target_pr_number": target_pr_number,
+        "target_head_sha": stale_review_decision_lock.normalize_head_sha(
+            expected_head_sha
+        ),
+        "lock_summary": classification.get("lock_summary"),
+        "evidence": classification.get("evidence"),
+        "reasons": list(classification.get("reasons") or []),
+        "manual_file_delete_forbidden": True,
+        "correction_as_generic_unlock_forbidden": True,
+        "durable_issue_handoff": stale_review_decision_lock.build_precise_mark_final_failure(
+            classification
+        ).get("durable_issue_handoff"),
+    }
 
 
 
@@ -6672,7 +7258,12 @@ def gitea_edit_pr(
         raise ValueError("At least one field to edit (title, body, state, base) must be provided.")
 
     closing = payload.get("state") == "closed"
-    verify_preflight_purity(remote, task="close_pr" if closing else None)
+    # Closing uses close_pr; non-closing title/body/base edits use edit_pr so
+    # the shared #604 anti-stomp inventory stays consistent with wiring.
+    if closing:
+        verify_preflight_purity(remote, task="close_pr")
+    else:
+        verify_preflight_purity(remote, task="edit_pr")
 
     # PR closure is a first-class capability, distinct from retitling or
     # rebasing edits (#216). Gate BEFORE auth/API setup so a blocked close
@@ -7164,6 +7755,25 @@ def gitea_merge_pr(
         reasons.extend(lease_block.get("reasons") or [])
         result["pr_work_lease"] = lease_block
         return result
+
+    # #604: common anti-stomp with live head + lease proof (typed blocker).
+    try:
+        _run_anti_stomp_preflight(
+            "merge_pr",
+            remote=remote,
+            worktree_path=worktree_path,
+            org=org,
+            repo=repo,
+            expected_head_sha=expected_head_sha,
+            live_head_sha=actual_sha,
+            require_head_sha=True,
+            foreign_lease=False,
+            terminal_lock_blocks=False,
+        )
+    except RuntimeError as exc:
+        reasons.append(str(exc))
+        return result
+
     if expected_head_sha and actual_sha and expected_head_sha != actual_sha:
         reasons.append(
             "expected head SHA does not match current PR head (fail closed)"
@@ -10040,7 +10650,11 @@ def gitea_acquire_reviewer_pr_lease(
             "permission_report": _permission_block_report("gitea.pr.comment"),
         }
 
-    _verify_role_mutation_workspace(remote, worktree=worktree, task="review_pr")
+    # task=acquire_reviewer_pr_lease so verify_preflight_purity runs shared #604
+    # anti-stomp for the declared lease-acquire mutation inventory entry.
+    _verify_role_mutation_workspace(
+        remote, worktree=worktree, task="acquire_reviewer_pr_lease"
+    )
     h, o, r = _resolve(remote, host, org, repo)
     auth = _auth(h)
     profile = get_profile()
@@ -10181,6 +10795,7 @@ def gitea_adopt_merger_pr_lease(
             "permission_report": _permission_block_report("gitea.pr.merge"),
         }
 
+    # task=adopt_merger_pr_lease so verify_preflight_purity runs shared #604 anti-stomp.
     _verify_role_mutation_workspace(
         remote, worktree=worktree, task="adopt_merger_pr_lease"
     )

stale_review_decision_lock.py

@@ -1,4 +1,4 @@
-"""Stale / moot #332 review-decision lock detection and cleanup policy (#594/#620).
+"""Stale / moot #332 review-decision lock detection and cleanup policy (#594/#620/#693).
 
 #332 correctly hard-stops a reviewer session after a terminal live review
 mutation. After #559 those locks are durable on disk, so they can outlive the
@@ -12,6 +12,11 @@ on head B of the **same open PR**. Same-head duplicates remain fail-closed.
 Open-PR lock *cleanup* remains forbidden unless the PR is truly merged/closed
 (#594); new-head re-review is allowed without deleting the durable lock.
 
+#693 scopes the terminal boundary by **PR number**: a terminal on open PR A
+must not block a fresh formal decision on open PR B on the same durable
+profile lock (cross-PR isolation). Correction authorization is scoped to the
+named prior review's PR/head and cannot unlock a different PR.
+
 This module is pure policy (no Gitea I/O). The MCP tool
 ``gitea_cleanup_stale_review_decision_lock`` fetches live PR state, calls these
 helpers, and only then clears durable state when cleanup is allowed.
@@ -80,17 +85,45 @@ def last_terminal_mutation(lock: dict | None) -> dict | None:
     return terminals[-1] if terminals else None
 
 
+def correction_applies(
+    lock: dict | None,
+    *,
+    pr_number: int | None = None,
+    expected_head_sha: str | None = None,
+) -> bool:
+    """True when operator correction is active and scoped to the target (#693).
+
+    Global ``correction_authorized`` alone is not enough: correction must name
+    the same PR (and head when recorded) as the decision being re-opened.
+    Missing scope fields on legacy locks fail closed (do not apply).
+    """
+    if not lock or not lock.get("correction_authorized"):
+        return False
+    corr_pr = lock.get("correction_pr_number")
+    if corr_pr is None:
+        # Legacy unscoped correction — refuse as generic unlock (#693).
+        return False
+    if pr_number is not None and int(corr_pr) != int(pr_number):
+        return False
+    corr_head = normalize_head_sha(lock.get("correction_head_sha"))
+    target = normalize_head_sha(expected_head_sha)
+    if corr_head and target and not heads_equal(corr_head, target):
+        return False
+    return True
+
+
 def prior_live_mutations_block_boundary(
     lock: dict | None,
     *,
     pr_number: int,
     expected_head_sha: str | None,
 ) -> bool:
-    """True when prior live mutations block a new decision for PR+head (#620).
+    """True when prior live mutations block a new decision for PR+head (#620/#693).
 
     Historical terminals on a **different head of the same PR** do not block.
-    Any prior mutation on another PR, the same head, or without a comparable
+    Terminals on a **different PR** do not block (#693 cross-PR isolation).
-    head SHA fails closed (blocks).
+    Same PR + same head (or same PR without a comparable head SHA) blocks
+    unless a scoped correction applies.
 
     Head resolution uses ``mutation_head_sha(m, lock)`` so pre-#620 ledgers
     that only stored ``ready_expected_head_sha`` still compare correctly
@@ -98,7 +131,9 @@ def prior_live_mutations_block_boundary(
     """
     if not lock:
         return False
-    if lock.get("correction_authorized"):
+    if correction_applies(
+        lock, pr_number=pr_number, expected_head_sha=expected_head_sha
+    ):
         return False
     prior = list(lock.get("live_mutations") or [])
     if not prior:
@@ -108,10 +143,14 @@ def prior_live_mutations_block_boundary(
         if not isinstance(m, dict):
             return True
         m_pr = m.get("pr_number")
+        if m_pr is None:
+            return True  # fail closed — unscoped mutation
+        if int(m_pr) != int(pr_number):
+            # #693: foreign-PR history on the shared durable lock does not block.
+            continue
         m_head = mutation_head_sha(m, lock)
         if (
-            m_pr == pr_number
+            target
-            and target
             and m_head
             and not heads_equal(m_head, target)
         ):
@@ -128,23 +167,34 @@ def terminal_boundary_allows_fresh_decision(
     expected_head_sha: str | None,
     operation: str,
 ) -> bool:
-    """Whether #332 hard-stop should yield for a new PR+head boundary (#620).
+    """Whether #332 hard-stop should yield for a new PR+head boundary (#620/#693).
 
-    Only for ``mark_ready`` / ``review`` / ``resume`` on the **same PR** when
+    For ``mark_ready`` / ``review`` / ``resume``:
-    the requested head differs from the last terminal's head. Merge is never
+
-    reopened by head change (approved head merge path is separate).
+    * **same PR, different head** — allowed (#620)
+    * **different PR than last terminal** — allowed (#693 cross-PR isolation)
+    * **same PR, same head** — not allowed (unless scoped correction)
+
+    Merge is never reopened by head change or cross-PR isolation (approved
+    head merge path is separate).
     """
     if operation not in ("mark_ready", "review", "resume"):
         return False
     if not lock:
         return False
-    if lock.get("correction_authorized"):
+    if correction_applies(
+        lock, pr_number=pr_number, expected_head_sha=expected_head_sha
+    ):
         return True
     last = last_terminal_mutation(lock)
     if last is None:
         return True
-    if last.get("pr_number") != pr_number:
+    last_pr = last.get("pr_number")
+    if last_pr is None:
         return False
+    if int(last_pr) != int(pr_number):
+        # #693: last terminal belongs to another PR — do not hard-stop this PR.
+        return True
     locked_head = mutation_head_sha(last, lock)
     target = normalize_head_sha(expected_head_sha)
     if not locked_head or not target:
@@ -440,6 +490,400 @@ def format_cleanup_audit_comment(audit: dict[str, Any]) -> str:
     return "\n".join(lines)
 
 
+# --- #693 classification / recovery / correction audit -----------------------
+
+# Deterministic classification labels for diagnostics and recovery routing.
+CLASS_NO_LOCK = "no_lock"
+CLASS_READY_FOR_TARGET = "ready_for_target"
+CLASS_IN_PROGRESS_SAME_HEAD = "in_progress_same_head"
+CLASS_TERMINAL_ACTIVE_SAME_HEAD = "terminal_active_same_head"
+CLASS_STALE_SUPERSEDED_HEAD = "stale_superseded_head"
+CLASS_FOREIGN_PR_TERMINAL = "foreign_pr_terminal"
+CLASS_MOOT_MERGED_CLOSED = "moot_merged_closed"
+CLASS_CORRECTION_ACTIVE = "correction_active"
+CLASS_SESSION_OR_PROFILE_MISMATCH = "session_or_profile_mismatch"
+CLASS_AMBIGUOUS = "ambiguous"
+
+
+def classify_review_decision_lock(
+    lock: dict | None,
+    *,
+    target_pr_number: int | None = None,
+    target_head_sha: str | None = None,
+    pr_live: dict | None = None,
+    pr_lookup_error: str | None = None,
+    active_profile_identity: str | None = None,
+    session_blockers: list[str] | None = None,
+) -> dict[str, Any]:
+    """Deterministic review-decision-lock classification (#693).
+
+    Returns classification, exact next_action, owner/evidence fields, and
+    whether mark_final / cleanup / correction are appropriate.
+    """
+    summary = lock_summary(lock)
+    target_head = normalize_head_sha(target_head_sha)
+    result: dict[str, Any] = {
+        "classification": CLASS_NO_LOCK,
+        "has_lock": lock is not None,
+        "lock_summary": summary,
+        "target_pr_number": target_pr_number,
+        "target_head_sha": target_head,
+        "last_terminal_pr": None,
+        "last_terminal_action": None,
+        "locked_head_sha": None,
+        "owner_profile_identity": (summary or {}).get("profile_identity"),
+        "session_profile": (summary or {}).get("session_profile"),
+        "updated_at": (summary or {}).get("updated_at"),
+        "correction_authorized": bool((lock or {}).get("correction_authorized")),
+        "correction_pr_number": (lock or {}).get("correction_pr_number"),
+        "correction_head_sha": normalize_head_sha(
+            (lock or {}).get("correction_head_sha")
+        ),
+        "mark_final_allowed": True,
+        "cleanup_allowed": False,
+        "correction_eligible": False,
+        "next_action": "gitea_resolve_task_capability(task='review_pr') then mark_final",
+        "reasons": [],
+        "evidence": {},
+    }
+
+    if lock is None:
+        result["reasons"].append("no review decision lock present")
+        return result
+
+    session_blockers = list(session_blockers or [])
+    if session_blockers:
+        result["classification"] = CLASS_SESSION_OR_PROFILE_MISMATCH
+        result["mark_final_allowed"] = False
+        result["next_action"] = (
+            "reconnect matching prgs-reviewer session or wait for lock TTL; "
+            "do not use gitea_authorize_review_correction as unlock; "
+            "do not delete session-state files"
+        )
+        result["reasons"].extend(session_blockers)
+        return result
+
+    stored = (
+        (lock.get("profile_identity") or lock.get("session_profile_lock") or "")
+        .strip()
+    )
+    active = (active_profile_identity or "").strip()
+    if active and stored and active != stored:
+        result["classification"] = CLASS_SESSION_OR_PROFILE_MISMATCH
+        result["mark_final_allowed"] = False
+        result["next_action"] = (
+            f"switch to profile '{stored}' or wait for moot cleanup; "
+            "do not use correction authorization as a generic unlock"
+        )
+        result["reasons"].append(
+            f"lock profile '{stored}' does not match active '{active}'"
+        )
+        return result
+
+    last = last_terminal_mutation(lock)
+    if last is None:
+        ready_pr = lock.get("ready_pr_number")
+        ready_head = normalize_head_sha(lock.get("ready_expected_head_sha"))
+        if (
+            target_pr_number is not None
+            and ready_pr == target_pr_number
+            and ready_head
+            and target_head
+            and heads_equal(ready_head, target_head)
+            and lock.get("final_review_decision_ready")
+        ):
+            result["classification"] = CLASS_IN_PROGRESS_SAME_HEAD
+            result["mark_final_allowed"] = True  # idempotent re-mark
+            result["next_action"] = (
+                "gitea_submit_pr_review with final_review_decision_ready=true "
+                "for the ready PR/head"
+            )
+            result["reasons"].append(
+                "final decision already marked ready for this PR/head (idempotent)"
+            )
+            return result
+        result["classification"] = CLASS_READY_FOR_TARGET
+        result["next_action"] = "gitea_mark_final_review_decision then submit"
+        result["reasons"].append("no terminal live mutations; mark_final allowed")
+        return result
+
+    last_pr = last.get("pr_number")
+    last_action = last.get("action")
+    locked_head = mutation_head_sha(last, lock)
+    result["last_terminal_pr"] = last_pr
+    result["last_terminal_action"] = last_action
+    result["locked_head_sha"] = locked_head
+    result["evidence"] = {
+        "last_review_id": last.get("review_id"),
+        "live_mutations_count": len(lock.get("live_mutations") or []),
+    }
+
+    if correction_applies(
+        lock, pr_number=target_pr_number, expected_head_sha=target_head
+    ):
+        result["classification"] = CLASS_CORRECTION_ACTIVE
+        result["mark_final_allowed"] = True
+        result["next_action"] = (
+            "gitea_mark_final_review_decision for the correction-scoped PR/head, "
+            "then submit once"
+        )
+        result["reasons"].append(
+            f"scoped correction active for PR #{lock.get('correction_pr_number')}"
+        )
+        return result
+
+    # Live state of last terminal PR when provided.
+    live = None
+    if pr_lookup_error:
+        result["classification"] = CLASS_AMBIGUOUS
+        result["mark_final_allowed"] = False
+        result["next_action"] = (
+            "retry diagnosis after live PR state is available; "
+            "fail closed under ambiguous evidence"
+        )
+        result["reasons"].append(f"live PR lookup failed: {pr_lookup_error}")
+        return result
+    if pr_live is not None:
+        live = classify_pr_live_state(pr_live)
+        result["evidence"]["last_terminal_pr_state"] = live.get("pr_state")
+        result["evidence"]["last_terminal_pr_merged"] = live.get("pr_merged")
+        if live.get("pr_merged_or_closed"):
+            result["classification"] = CLASS_MOOT_MERGED_CLOSED
+            result["cleanup_allowed"] = True
+            result["mark_final_allowed"] = target_pr_number is not None and (
+                int(last_pr) != int(target_pr_number)
+                if last_pr is not None and target_pr_number is not None
+                else True
+            )
+            result["next_action"] = (
+                "gitea_cleanup_stale_review_decision_lock(apply=true, "
+                f"expected_terminal_pr={last_pr}) then mark_final on the target PR"
+            )
+            result["reasons"].append(
+                f"terminal on PR #{last_pr} is moot (merged/closed); cleanup allowed"
+            )
+            return result
+
+    if target_pr_number is None:
+        result["classification"] = CLASS_AMBIGUOUS
+        result["mark_final_allowed"] = False
+        result["next_action"] = "re-run diagnosis with target_pr_number"
+        result["reasons"].append("target_pr_number required for open-PR classification")
+        return result
+
+    if last_pr is not None and int(last_pr) != int(target_pr_number):
+        # Cross-PR isolation: foreign terminal is history, not a block.
+        result["classification"] = CLASS_FOREIGN_PR_TERMINAL
+        result["mark_final_allowed"] = True
+        result["correction_eligible"] = False  # must not use correction to "unlock"
+        result["next_action"] = (
+            f"gitea_mark_final_review_decision(pr_number={target_pr_number}, ...) "
+            f"— foreign terminal on PR #{last_pr} does not block (#693); "
+            "do not call gitea_authorize_review_correction for cross-PR unlock"
+        )
+        result["reasons"].append(
+            f"last terminal is {last_action} on foreign open/closed PR #{last_pr}; "
+            f"target PR #{target_pr_number} is isolated (#693)"
+        )
+        return result
+
+    # Same PR as target.
+    if (
+        locked_head
+        and target_head
+        and not heads_equal(locked_head, target_head)
+    ):
+        result["classification"] = CLASS_STALE_SUPERSEDED_HEAD
+        result["mark_final_allowed"] = True
+        result["next_action"] = (
+            f"gitea_mark_final_review_decision with expected_head_sha="
+            f"{target_head} (#620 same-PR new head)"
+        )
+        result["reasons"].append(
+            f"terminal {last_action} on head {locked_head[:12]}…; target head "
+            f"{target_head[:12]}… — fresh formal review allowed without cleanup"
+        )
+        return result
+
+    # Same PR + same head (or missing head comparison) — active terminal.
+    result["classification"] = CLASS_TERMINAL_ACTIVE_SAME_HEAD
+    result["mark_final_allowed"] = False
+    result["correction_eligible"] = True
+    result["next_action"] = (
+        "if the prior verdict was mistaken: gitea_authorize_review_correction "
+        f"with prior_review_id={last.get('review_id')}, "
+        f"prior_review_state={last_action}, target_pr_number={target_pr_number}, "
+        "operator_authorized=true, then re-mark once; "
+        "if the prior verdict is correct: stop and hand off (do not duplicate)"
+    )
+    result["reasons"].append(
+        f"terminal {last_action} already recorded for PR #{target_pr_number} "
+        f"at this head; same-head duplicate blocked (#332/#620)"
+    )
+    return result
+
+
+def build_precise_mark_final_failure(
+    classification: dict[str, Any],
+) -> dict[str, Any]:
+    """One precise recovery instruction + durable issue handoff payload (#693 AC4/8)."""
+    cls = classification.get("classification")
+    next_action = classification.get("next_action") or (
+        "stop and create a durable Gitea issue with lock evidence"
+    )
+    reasons = list(classification.get("reasons") or [])
+    reasons.append(f"exact_next_action: {next_action}")
+    handoff = {
+        "required": cls
+        in (
+            CLASS_AMBIGUOUS,
+            CLASS_SESSION_OR_PROFILE_MISMATCH,
+            CLASS_TERMINAL_ACTIVE_SAME_HEAD,
+        )
+        and not classification.get("mark_final_allowed"),
+        "title_hint": (
+            "Review-decision-lock recovery failed during formal review"
+        ),
+        "classification": cls,
+        "exact_next_action": next_action,
+        "owner_profile_identity": classification.get("owner_profile_identity"),
+        "last_terminal_pr": classification.get("last_terminal_pr"),
+        "last_terminal_action": classification.get("last_terminal_action"),
+        "locked_head_sha": classification.get("locked_head_sha"),
+        "target_pr_number": classification.get("target_pr_number"),
+        "target_head_sha": classification.get("target_head_sha"),
+        "evidence": classification.get("evidence") or {},
+        "instruction": (
+            "If recovery cannot complete with the exact_next_action above, "
+            "create or update a durable Gitea issue with this payload and stop; "
+            "do not delete session-state files; do not misuse correction as unlock."
+        ),
+    }
+    return {
+        "reasons": reasons,
+        "classification": cls,
+        "exact_next_action": next_action,
+        "durable_issue_handoff": handoff,
+    }
+
+
+def build_correction_audit_record(
+    *,
+    prior_review_id: int | None,
+    prior_review_state: str | None,
+    target_pr_number: int | None,
+    target_head_sha: str | None,
+    reason: str | None,
+    actor_username: str | None,
+    profile_name: str | None,
+    authorized: bool,
+) -> dict[str, Any]:
+    """Structured durable audit for review-correction authorization (#693)."""
+    return {
+        "event": "review_correction_authorization",
+        "issue_ref": "#693",
+        "authorized": bool(authorized),
+        "timestamp": datetime.now(timezone.utc).isoformat(),
+        "actor_username": actor_username,
+        "profile_name": profile_name,
+        "prior_review_id": prior_review_id,
+        "prior_review_state": prior_review_state,
+        "target_pr_number": target_pr_number,
+        "target_head_sha": normalize_head_sha(target_head_sha),
+        "reason": reason,
+        "scope": "same_pr_head_only",
+    }
+
+
+def format_correction_audit_comment(audit: dict[str, Any]) -> str:
+    """Markdown body for a thread-visible correction authorization audit."""
+    status = "AUTHORIZED" if audit.get("authorized") else "DENIED"
+    lines = [
+        "## Review correction authorization audit (#693)",
+        "",
+        f"Status: **{status}**",
+        "",
+        f"- actor: `{audit.get('actor_username')}`",
+        f"- profile: `{audit.get('profile_name')}`",
+        f"- timestamp: `{audit.get('timestamp')}`",
+        f"- prior_review_id: `{audit.get('prior_review_id')}`",
+        f"- prior_review_state: `{audit.get('prior_review_state')}`",
+        f"- target_pr: `#{audit.get('target_pr_number')}`",
+        f"- target_head_sha: `{audit.get('target_head_sha')}`",
+        f"- reason: {audit.get('reason')}",
+        f"- scope: `{audit.get('scope')}` (cannot unlock a different PR)",
+        "",
+        "This is **not** a generic decision-lock unlock. Cross-PR recovery "
+        "uses isolation (#693) or moot cleanup (#594), never correction.",
+    ]
+    return "\n".join(lines)
+
+
+def assess_open_pr_decision_lock_recovery(
+    lock: dict | None,
+    *,
+    target_pr_number: int,
+    target_head_sha: str | None,
+    last_terminal_pr_live: dict | None = None,
+    pr_lookup_error: str | None = None,
+    active_profile_identity: str | None = None,
+    session_blockers: list[str] | None = None,
+    controller_recovery_authorized: bool = False,
+) -> dict[str, Any]:
+    """Assess guarded recovery for decision locks affecting an open target PR (#693).
+
+    Recovery here means *workflow recovery routing*, not necessarily lock wipe.
+    Foreign-PR terminals are recoverable by isolation (mark_final allowed).
+    Moot terminals use #594 cleanup. Same-head active terminals refuse wipe.
+    """
+    classification = classify_review_decision_lock(
+        lock,
+        target_pr_number=target_pr_number,
+        target_head_sha=target_head_sha,
+        pr_live=last_terminal_pr_live,
+        pr_lookup_error=pr_lookup_error,
+        active_profile_identity=active_profile_identity,
+        session_blockers=session_blockers,
+    )
+    cls = classification["classification"]
+    recovery_allowed = False
+    recovery_mode = None
+    if cls == CLASS_FOREIGN_PR_TERMINAL:
+        recovery_allowed = True
+        recovery_mode = "cross_pr_isolation"
+    elif cls == CLASS_STALE_SUPERSEDED_HEAD:
+        recovery_allowed = True
+        recovery_mode = "same_pr_new_head"
+    elif cls == CLASS_MOOT_MERGED_CLOSED:
+        recovery_allowed = True
+        recovery_mode = "moot_cleanup"
+    elif cls == CLASS_READY_FOR_TARGET:
+        recovery_allowed = True
+        recovery_mode = "none_required"
+    elif cls == CLASS_CORRECTION_ACTIVE:
+        recovery_allowed = True
+        recovery_mode = "scoped_correction"
+    elif cls == CLASS_TERMINAL_ACTIVE_SAME_HEAD:
+        recovery_allowed = False
+        recovery_mode = "correction_only_if_mistake"
+    else:
+        recovery_allowed = False
+        recovery_mode = "fail_closed"
+
+    if recovery_mode == "moot_cleanup" and not controller_recovery_authorized:
+        # Cleanup still needs apply + capability; assess reports path.
+        pass
+
+    return {
+        **classification,
+        "recovery_allowed": recovery_allowed,
+        "recovery_mode": recovery_mode,
+        "controller_recovery_authorized": bool(controller_recovery_authorized),
+        "manual_file_delete_forbidden": True,
+        "correction_as_generic_unlock_forbidden": True,
+    }
+
+
 # ---------------------------------------------------------------------------
 # #709 cross-profile cleanup, overwrite protection, recovery provenance
 # ---------------------------------------------------------------------------

task_capability_map.py

@@ -60,6 +60,15 @@ TASK_CAPABILITY_MAP: dict[str, dict[str, str]] = {
         "permission": "gitea.pr.close",
         "role": "author",
     },
+    # Non-closing PR metadata edits (title/body/base). Closing uses close_pr.
+    "edit_pr": {
+        "permission": "gitea.pr.create",
+        "role": "author",
+    },
+    "gitea_edit_pr": {
+        "permission": "gitea.pr.create",
+        "role": "author",
+    },
     "address_pr_change_requests": {
         "permission": "gitea.branch.push",
         "role": "author",
@@ -68,10 +77,22 @@ TASK_CAPABILITY_MAP: dict[str, dict[str, str]] = {
         "permission": "gitea.pr.review",
         "role": "reviewer",
     },
+    "submit_pr_review": {
+        "permission": "gitea.pr.review",
+        "role": "reviewer",
+    },
     "merge_pr": {
         "permission": "gitea.pr.merge",
         "role": "merger",
     },
+    "acquire_reviewer_pr_lease": {
+        "permission": "gitea.pr.comment",
+        "role": "reviewer",
+    },
+    "gitea_acquire_reviewer_pr_lease": {
+        "permission": "gitea.pr.comment",
+        "role": "reviewer",
+    },
     # #695 AC8: controller quarantine of contaminated formal reviews.
     # Apply path posts an append-only forensic audit comment (pr.comment).
     "quarantine_contaminated_review": {
@@ -127,6 +148,23 @@ TASK_CAPABILITY_MAP: dict[str, dict[str, str]] = {
         "permission": "gitea.pr.review",
         "role": "reviewer",
     },
+    # #693: read-only classification of durable decision locks (incl. open PRs).
+    "diagnose_review_decision_lock": {
+        "permission": "gitea.read",
+        "role": "reviewer",
+    },
+    "gitea_diagnose_review_decision_lock": {
+        "permission": "gitea.read",
+        "role": "reviewer",
+    },
+    "authorize_review_correction": {
+        "permission": "gitea.pr.review",
+        "role": "reviewer",
+    },
+    "gitea_authorize_review_correction": {
+        "permission": "gitea.pr.review",
+        "role": "reviewer",
+    },
     # #709: truthful absence-of-proof recovery (server-side auth + record + consume).
     # Dedicated mutation capability — gitea.read is insufficient (review 434 F1).
     "issue_irrecoverable_provenance_authorization": {

tests/test_head_scoped_review_decision_lock.py

@@ -24,6 +24,10 @@ HEAD_C = "c" * 40
 
 
 def _lock(mutations=None, correction=False, ready_pr=None, ready_head=None, ready_action=None):
+    mutations = list(mutations or [])
+    corr_pr = None
+    if correction and mutations:
+        corr_pr = mutations[-1].get("pr_number")
     return {
         "task": "review_pr",
         "remote": "prgs",
@@ -40,9 +44,11 @@ def _lock(mutations=None, correction=False, ready_pr=None, ready_head=None, read
         "ready_remote": "prgs" if ready_pr else None,
         "ready_org": "Scaled-Tech-Consulting" if ready_pr else None,
         "ready_repo": "Gitea-Tools" if ready_pr else None,
-        "live_mutations": list(mutations or []),
+        "live_mutations": mutations,
         "correction_authorized": correction,
-        "correction_reason": None,
+        "correction_reason": "test" if correction else None,
+        "correction_pr_number": corr_pr,
+        "correction_head_sha": None,
     }
 
 
@@ -174,12 +180,13 @@ class TestHardStopHeadScope(unittest.TestCase):
         self.assertTrue(reasons)
         self.assertIn("#332", reasons[0])
 
-    def test_rc_head_a_blocks_other_pr(self):
+    def test_rc_head_a_allows_other_pr_via_cross_pr_isolation(self):
+        """#693: foreign-PR terminal must not hard-stop mark_ready on another PR."""
         _seed([RC_619_HEAD_A], ready_pr=619, ready_head=HEAD_A)
         reasons = mcp_server.terminal_review_hard_stop_reasons(
             700, "mark_ready", expected_head_sha=HEAD_B
         )
-        self.assertTrue(reasons)
+        self.assertEqual(reasons, [])
 
     def test_legacy_619_ledger_allows_new_head(self):
         """PR #619-style durable lock without mutation head_sha."""

tests/test_issue_693_review_decision_lock_recovery.py

@@ -0,0 +1,427 @@
+"""Review-decision-lock recovery / cross-PR isolation (#693).
+
+Reproduces the PR #688 → PR #692 formal-review sequence:
+
+  * durable lock holds REQUEST_CHANGES on open PR #688 @ head A (review_id 425)
+  * reviewer leases PR #692 @ head B (6d86db…)
+  * mark_final for #692 must succeed without correction unlock
+  * cleanup of open #688 terminal remains forbidden (#594)
+  * authorize_review_correction for #688 cannot unlock #692
+  * eventual #692 APPROVE is unique and head-bound (review_id 426)
+  * mark_final is idempotent for same PR/action/head
+  * diagnosis returns one exact next_action + durable handoff payload
+"""
+
+from __future__ import annotations
+
+import os
+import unittest
+from unittest.mock import patch
+
+import mcp_server
+import review_workflow_load
+import stale_review_decision_lock as srdl
+
+# PR #688 / #692 incident fixtures (sanitized reconstruction from issue #693)
+HEAD_688 = "c7a444eb4b41cf916fdbd20a4999ffd78af496d0"
+HEAD_692 = "6d86db793bbdfaed16bd54d93171f1dd66f234ca"
+PR_A = 688
+PR_B = 692
+REVIEW_ID_A = 425
+REVIEW_ID_B = 426
+
+RC_688 = {
+    "pr_number": PR_A,
+    "action": "request_changes",
+    "review_id": REVIEW_ID_A,
+    "review_state": "request_changes",
+    "head_sha": HEAD_688,
+}
+APPROVE_692 = {
+    "pr_number": PR_B,
+    "action": "approve",
+    "review_id": REVIEW_ID_B,
+    "review_state": "approve",
+    "head_sha": HEAD_692,
+}
+
+
+def _lock(mutations=None, **kwargs):
+    from datetime import datetime, timezone
+
+    now = datetime.now(timezone.utc).isoformat()
+    base = {
+        "task": "review_pr",
+        "remote": "prgs",
+        "org": "Scaled-Tech-Consulting",
+        "repo": "Gitea-Tools",
+        "session_pid": os.getpid(),
+        "session_profile": "prgs-reviewer",
+        "session_profile_lock": "prgs-reviewer",
+        "profile_identity": "prgs-reviewer",
+        "final_review_decision_ready": False,
+        "ready_pr_number": None,
+        "ready_action": None,
+        "ready_expected_head_sha": None,
+        "ready_remote": None,
+        "ready_org": None,
+        "ready_repo": None,
+        "live_mutations": list(mutations or []),
+        "correction_authorized": False,
+        "correction_reason": None,
+        "correction_pr_number": None,
+        "correction_head_sha": None,
+        "updated_at": now,
+        "recorded_at": now,
+        "writer_pid": os.getpid(),
+    }
+    base.update(kwargs)
+    # Ensure TTL fields stay fresh unless the caller is testing expiry.
+    if "recorded_at" not in kwargs:
+        base["recorded_at"] = now
+    if "updated_at" not in kwargs:
+        base["updated_at"] = now
+    return base
+
+
+REVIEWER_ENV = {
+    "GITEA_PROFILE_NAME": "prgs-reviewer",
+    "GITEA_ALLOWED_OPERATIONS": (
+        "gitea.read,gitea.pr.review,gitea.pr.approve,"
+        "gitea.pr.request_changes,gitea.pr.comment"
+    ),
+    "GITEA_SESSION_PROFILE_LOCK": "prgs-reviewer",
+}
+
+REVIEWER_PROFILE = {
+    "profile_name": "prgs-reviewer",
+    "allowed_operations": [
+        "gitea.read",
+        "gitea.pr.review",
+        "gitea.pr.approve",
+        "gitea.pr.request_changes",
+        "gitea.pr.comment",
+    ],
+    "forbidden_operations": ["gitea.pr.merge"],
+}
+
+
+def _seed(mutations=None, **kwargs):
+    review_workflow_load.record_review_workflow_load(mcp_server.PROJECT_ROOT)
+    mcp_server._save_review_decision_lock(_lock(mutations, **kwargs))
+    mcp_server.gitea_load_review_workflow()
+
+
+def _no_lease():
+    return {"block": False, "reasons": [], "mutation_allowed": True}
+
+
+def _open_pr(number, head):
+    return {
+        "number": number,
+        "state": "open",
+        "merged": False,
+        "merged_at": None,
+        "head": {"sha": head},
+    }
+
+
+class TestCrossPrIsolationPure(unittest.TestCase):
+    def test_foreign_terminal_does_not_block_mark_boundary(self):
+        lock = _lock([RC_688])
+        self.assertFalse(
+            srdl.prior_live_mutations_block_boundary(
+                lock, pr_number=PR_B, expected_head_sha=HEAD_692
+            )
+        )
+        self.assertTrue(
+            srdl.prior_live_mutations_block_boundary(
+                lock, pr_number=PR_A, expected_head_sha=HEAD_688
+            )
+        )
+
+    def test_terminal_boundary_allows_fresh_decision_on_other_pr(self):
+        lock = _lock([RC_688])
+        self.assertTrue(
+            srdl.terminal_boundary_allows_fresh_decision(
+                lock,
+                pr_number=PR_B,
+                expected_head_sha=HEAD_692,
+                operation="mark_ready",
+            )
+        )
+        self.assertFalse(
+            srdl.terminal_boundary_allows_fresh_decision(
+                lock,
+                pr_number=PR_A,
+                expected_head_sha=HEAD_688,
+                operation="mark_ready",
+            )
+        )
+
+    def test_unscoped_correction_does_not_apply(self):
+        lock = _lock([RC_688], correction_authorized=True, correction_reason="x")
+        # Missing correction_pr_number → fail closed (#693)
+        self.assertFalse(
+            srdl.correction_applies(lock, pr_number=PR_A, expected_head_sha=HEAD_688)
+        )
+
+    def test_scoped_correction_only_for_named_pr(self):
+        lock = _lock(
+            [RC_688],
+            correction_authorized=True,
+            correction_reason="mistake",
+            correction_pr_number=PR_A,
+            correction_head_sha=HEAD_688,
+        )
+        self.assertTrue(
+            srdl.correction_applies(lock, pr_number=PR_A, expected_head_sha=HEAD_688)
+        )
+        self.assertFalse(
+            srdl.correction_applies(lock, pr_number=PR_B, expected_head_sha=HEAD_692)
+        )
+
+
+class TestClassification(unittest.TestCase):
+    def test_foreign_pr_terminal_classification(self):
+        lock = _lock([RC_688])
+        c = srdl.classify_review_decision_lock(
+            lock,
+            target_pr_number=PR_B,
+            target_head_sha=HEAD_692,
+            pr_live=_open_pr(PR_A, HEAD_688),
+            active_profile_identity="prgs-reviewer",
+        )
+        self.assertEqual(c["classification"], srdl.CLASS_FOREIGN_PR_TERMINAL)
+        self.assertTrue(c["mark_final_allowed"])
+        self.assertFalse(c["correction_eligible"])
+        self.assertIn("do not call gitea_authorize_review_correction", c["next_action"])
+
+    def test_same_head_terminal_classification(self):
+        lock = _lock([RC_688])
+        c = srdl.classify_review_decision_lock(
+            lock,
+            target_pr_number=PR_A,
+            target_head_sha=HEAD_688,
+            pr_live=_open_pr(PR_A, HEAD_688),
+        )
+        self.assertEqual(c["classification"], srdl.CLASS_TERMINAL_ACTIVE_SAME_HEAD)
+        self.assertFalse(c["mark_final_allowed"])
+        self.assertTrue(c["correction_eligible"])
+
+    def test_precise_failure_includes_durable_handoff(self):
+        lock = _lock([RC_688])
+        c = srdl.classify_review_decision_lock(
+            lock, target_pr_number=PR_A, target_head_sha=HEAD_688
+        )
+        fail = srdl.build_precise_mark_final_failure(c)
+        self.assertIn("exact_next_action", fail)
+        self.assertIn("durable_issue_handoff", fail)
+        self.assertTrue(fail["durable_issue_handoff"]["required"])
+
+
+class TestPr692Sequence(unittest.TestCase):
+    def setUp(self):
+        self._env = patch.dict(os.environ, REVIEWER_ENV, clear=False)
+        self._env.start()
+        self._prof = patch.object(
+            mcp_server, "get_profile", return_value=REVIEWER_PROFILE
+        )
+        self._prof.start()
+
+    def tearDown(self):
+        self._prof.stop()
+        self._env.stop()
+        mcp_server._save_review_decision_lock(None)
+        review_workflow_load.clear_review_workflow_load()
+
+    def test_mark_final_692_succeeds_with_open_688_terminal(self):
+        _seed([RC_688], writer_pid=25883, session_pid=60615)
+        with patch("mcp_server._list_pr_lease_comments", return_value=[]), patch(
+            "mcp_server._pr_work_lease_reviewer_block", return_value=_no_lease()
+        ), patch.object(
+            mcp_server,
+            "gitea_check_pr_eligibility",
+            return_value={"head_sha": HEAD_692, "eligible": True},
+        ):
+            result = mcp_server.gitea_mark_final_review_decision(
+                pr_number=PR_B,
+                action="approve",
+                expected_head_sha=HEAD_692,
+                remote="prgs",
+                org="Scaled-Tech-Consulting",
+                repo="Gitea-Tools",
+            )
+        self.assertTrue(result["marked_ready"], result.get("reasons"))
+        lock = mcp_server._load_review_decision_lock()
+        self.assertEqual(lock["ready_pr_number"], PR_B)
+        self.assertEqual(
+            srdl.normalize_head_sha(lock["ready_expected_head_sha"]), HEAD_692
+        )
+        # Foreign terminal history preserved (non-destructive isolation).
+        self.assertEqual(lock["live_mutations"][0]["pr_number"], PR_A)
+
+    def test_mark_final_idempotent_same_binding(self):
+        _seed(
+            [RC_688],
+            final_review_decision_ready=True,
+            ready_pr_number=PR_B,
+            ready_action="approve",
+            ready_expected_head_sha=HEAD_692,
+            ready_remote="prgs",
+            ready_org="Scaled-Tech-Consulting",
+            ready_repo="Gitea-Tools",
+        )
+        with patch("mcp_server._list_pr_lease_comments", return_value=[]), patch(
+            "mcp_server._pr_work_lease_reviewer_block", return_value=_no_lease()
+        ), patch.object(
+            mcp_server,
+            "gitea_check_pr_eligibility",
+            return_value={"head_sha": HEAD_692, "eligible": True},
+        ):
+            result = mcp_server.gitea_mark_final_review_decision(
+                pr_number=PR_B,
+                action="approve",
+                expected_head_sha=HEAD_692,
+                remote="prgs",
+                org="Scaled-Tech-Consulting",
+                repo="Gitea-Tools",
+            )
+        self.assertTrue(result["marked_ready"])
+        self.assertTrue(result.get("idempotent"))
+
+    def test_cleanup_still_forbidden_while_688_open(self):
+        _seed([RC_688])
+        assessment = srdl.assess_stale_review_decision_lock(
+            mcp_server._load_review_decision_lock(),
+            pr_live=_open_pr(PR_A, HEAD_688),
+            active_profile_identity="prgs-reviewer",
+        )
+        self.assertFalse(assessment["cleanup_allowed"])
+        self.assertFalse(assessment["is_moot"])
+
+    def test_correction_cannot_unlock_different_pr(self):
+        _seed([RC_688])
+        r = mcp_server.gitea_authorize_review_correction(
+            prior_review_id=REVIEW_ID_A,
+            prior_review_state="request_changes",
+            reason="try unlock 692",
+            operator_authorized=True,
+            target_pr_number=PR_B,
+            remote="prgs",
+            org="Scaled-Tech-Consulting",
+            repo="Gitea-Tools",
+            post_audit_comment=False,
+        )
+        self.assertFalse(r["authorized"])
+        self.assertTrue(any("different PR" in x for x in r["reasons"]))
+
+    def test_scoped_correction_for_same_pr_posts_audit(self):
+        _seed([RC_688])
+        with patch(
+            "mcp_server._authenticated_username", return_value="sysadmin"
+        ), patch(
+            "mcp_server.get_auth_header", return_value="Basic dGVzdDp0ZXN0"
+        ), patch(
+            "mcp_server._auth", return_value="Basic dGVzdDp0ZXN0"
+        ), patch("mcp_server.api_request", return_value={"id": 99901}):
+            r = mcp_server.gitea_authorize_review_correction(
+                prior_review_id=REVIEW_ID_A,
+                prior_review_state="request_changes",
+                reason="mistaken RC wording",
+                operator_authorized=True,
+                target_pr_number=PR_A,
+                expected_head_sha=HEAD_688,
+                remote="prgs",
+                org="Scaled-Tech-Consulting",
+                repo="Gitea-Tools",
+                post_audit_comment=True,
+            )
+        self.assertTrue(r["authorized"], r.get("reasons"))
+        self.assertEqual(r.get("correction_pr_number"), PR_A)
+        self.assertEqual(
+            r.get("audit_comment_id"),
+            99901,
+            r.get("audit_comment_skipped") or r.get("audit_comment_error") or r,
+        )
+
+    def test_diagnose_foreign_terminal_next_action(self):
+        _seed([RC_688])
+        with patch(
+            "mcp_server._authenticated_username", return_value="sysadmin"
+        ), patch(
+            "mcp_server.get_auth_header", return_value="Basic dGVzdDp0ZXN0"
+        ), patch(
+            "mcp_server._auth", return_value="Basic dGVzdDp0ZXN0"
+        ), patch("mcp_server.api_request", return_value=_open_pr(PR_A, HEAD_688)):
+            d = mcp_server.gitea_diagnose_review_decision_lock(
+                target_pr_number=PR_B,
+                expected_head_sha=HEAD_692,
+                remote="prgs",
+                org="Scaled-Tech-Consulting",
+                repo="Gitea-Tools",
+            )
+        self.assertTrue(d["success"], d.get("reasons"))
+        self.assertEqual(d["classification"], srdl.CLASS_FOREIGN_PR_TERMINAL)
+        self.assertTrue(d["mark_final_allowed"])
+        self.assertIn("mark_final", d["exact_next_action"])
+        self.assertTrue(d["correction_as_generic_unlock_forbidden"])
+
+    def test_approval_ledger_unique_and_bound_after_sequence(self):
+        """After mark_final + record mutation, ledger binds unique approve to 692 head."""
+        _seed([RC_688])
+        with patch("mcp_server._list_pr_lease_comments", return_value=[]), patch(
+            "mcp_server._pr_work_lease_reviewer_block", return_value=_no_lease()
+        ), patch.object(
+            mcp_server,
+            "gitea_check_pr_eligibility",
+            return_value={"head_sha": HEAD_692, "eligible": True},
+        ):
+            marked = mcp_server.gitea_mark_final_review_decision(
+                pr_number=PR_B,
+                action="approve",
+                expected_head_sha=HEAD_692,
+                remote="prgs",
+                org="Scaled-Tech-Consulting",
+                repo="Gitea-Tools",
+            )
+        self.assertTrue(marked["marked_ready"])
+        mcp_server.record_live_review_mutation(PR_B, "approve", REVIEW_ID_B)
+        lock = mcp_server._load_review_decision_lock()
+        terminals = [
+            m
+            for m in lock["live_mutations"]
+            if m.get("action") in srdl.TERMINAL_REVIEW_ACTIONS
+            and m.get("pr_number") == PR_B
+        ]
+        self.assertEqual(len(terminals), 1)
+        self.assertEqual(terminals[0]["review_id"], REVIEW_ID_B)
+        self.assertEqual(
+            srdl.normalize_head_sha(terminals[0].get("head_sha")), HEAD_692
+        )
+        # Same-head duplicate still blocked.
+        self.assertTrue(
+            srdl.prior_live_mutations_block_boundary(
+                lock, pr_number=PR_B, expected_head_sha=HEAD_692
+            )
+        )
+
+
+class TestSessionRestartWriterPid(unittest.TestCase):
+    def tearDown(self):
+        mcp_server._save_review_decision_lock(None)
+        review_workflow_load.clear_review_workflow_load()
+
+    def test_writer_pid_change_does_not_inherit_foreign_block(self):
+        # session_pid 60615 origin, writer later 25883 — still foreign isolation.
+        _seed([RC_688], session_pid=60615, writer_pid=25883)
+        self.assertEqual(
+            mcp_server.terminal_review_hard_stop_reasons(
+                PR_B, "mark_ready", expected_head_sha=HEAD_692
+            ),
+            [],
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_mcp_server.py

@@ -2567,15 +2567,18 @@ class TestSubmitPrReview(unittest.TestCase):
         lock = _load_review_decision_lock() or {}
         lock["live_mutations"] = [{"pr_number": 8, "action": "approve", "review_id": 42, "review_state": "approve"}]
         _save_review_decision_lock(lock)
-        r = gitea_authorize_review_correction(
+        with patch("mcp_server.api_request", return_value={"id": 9001}):
-            prior_review_id=42,
+            r = gitea_authorize_review_correction(
-            prior_review_state="approve",
+                prior_review_id=42,
-            reason="typo",
+                prior_review_state="approve",
-            operator_authorized=True,
+                reason="typo",
-        )
+                operator_authorized=True,
+                target_pr_number=8,
+            )
         self.assertTrue(r["authorized"])
         lock = _load_review_decision_lock()
         self.assertTrue(lock["correction_authorized"])
+        self.assertEqual(lock["correction_pr_number"], 8)
 
     def test_authorize_review_correction_mismatch(self):
         from mcp_server import _load_review_decision_lock, _save_review_decision_lock
@@ -2589,6 +2592,7 @@ class TestSubmitPrReview(unittest.TestCase):
             prior_review_state="approve",
             reason="typo",
             operator_authorized=True,
+            target_pr_number=8,
         )
         self.assertFalse(r["authorized"])
         self.assertTrue(any("prior review ID" in x for x in r["reasons"]))
@@ -2599,10 +2603,22 @@ class TestSubmitPrReview(unittest.TestCase):
             prior_review_state="request_changes",
             reason="typo",
             operator_authorized=True,
+            target_pr_number=8,
         )
         self.assertFalse(r["authorized"])
         self.assertTrue(any("prior review state" in x for x in r["reasons"]))
 
+        # Cross-PR unlock refused (#693)
+        r = gitea_authorize_review_correction(
+            prior_review_id=42,
+            prior_review_state="approve",
+            reason="unlock other pr",
+            operator_authorized=True,
+            target_pr_number=692,
+        )
+        self.assertFalse(r["authorized"])
+        self.assertTrue(any("different PR" in x for x in r["reasons"]))
+
     def test_authorize_review_correction_requires_operator_auth(self):
         from mcp_server import _load_review_decision_lock, _save_review_decision_lock
         lock = _load_review_decision_lock() or {}
@@ -2615,6 +2631,7 @@ class TestSubmitPrReview(unittest.TestCase):
             prior_review_state="approve",
             reason="typo",
             operator_authorized=False,
+            target_pr_number=8,
         )
         self.assertFalse(r["authorized"])
         self.assertTrue(any("operator authorization" in x for x in r["reasons"]))
@@ -2672,6 +2689,7 @@ class TestSubmitPrReview(unittest.TestCase):
                     prior_review_state="approve",
                     reason="operator approved correcting mistaken approve",
                     operator_authorized=True,
+                    target_pr_number=8,
                 )
                 _mark_request_changes_ready(remote="prgs")
                 second = gitea_submit_pr_review(

tests/test_stale_review_decision_lock_cleanup.py

@@ -188,20 +188,32 @@ class TestActiveHardStopPreserved(unittest.TestCase):
         mcp_server._save_review_decision_lock(None)
         mcp_server.review_workflow_load.clear_review_workflow_load()
 
-    def test_open_approve_still_blocks_other_pr_mark_ready(self):
+    def test_open_approve_blocks_same_pr_not_other_pr_mark_ready(self):
-        _seed([APPROVED_OPEN])
+        _seed([APPROVED_OPEN])  # approve on PR #700
-        reasons = mcp_server.terminal_review_hard_stop_reasons(592, "mark_ready")
+        # Same PR still hard-stopped for mark_ready.
-        self.assertTrue(reasons)
+        reasons_same = mcp_server.terminal_review_hard_stop_reasons(
-        self.assertIn("#332", reasons[0])
+            700, "mark_ready"
-        self.assertIn("gitea_cleanup_stale_review_decision_lock", reasons[0])
+        )
+        self.assertTrue(reasons_same)
+        self.assertIn("#332", reasons_same[0])
+        # #693: other PR may mark_ready without cleanup.
+        self.assertEqual(
+            mcp_server.terminal_review_hard_stop_reasons(592, "mark_ready"),
+            [],
+        )
 
-    def test_request_changes_still_blocks_everything(self):
+    def test_request_changes_still_blocks_same_pr(self):
-        _seed([RC_OPEN])
+        _seed([RC_OPEN])  # request_changes on PR #701
         for op in ("merge", "mark_ready", "review"):
             self.assertTrue(
-                mcp_server.terminal_review_hard_stop_reasons(592, op),
+                mcp_server.terminal_review_hard_stop_reasons(701, op),
                 msg=op,
             )
+        # Foreign PR review path is open (#693).
+        self.assertEqual(
+            mcp_server.terminal_review_hard_stop_reasons(592, "mark_ready"),
+            [],
+        )
 
 
 # --------------------------------------------------------------------------- #

tests/test_terminal_review_hard_stop.py

@@ -1,10 +1,10 @@
-"""Tests for the session hard-stop after a terminal review mutation (#332).
+"""Tests for the session hard-stop after a terminal review mutation (#332/#693).
 
 Extends the single-terminal-decision machinery (#211): after a live
-REQUEST_CHANGES the run must stop; after an APPROVE only the merge sequence
+REQUEST_CHANGES on a PR head the same-head path must stop; after an APPROVE
-for that same PR may continue; a different PR can never be reviewed or
+only the merge sequence for that same PR may continue; #693 allows a
-merged in the same run; duplicate REQUEST_CHANGES at an unchanged head is
+*different* PR to be mark_ready/review in the same durable lock (cross-PR
-suppressed.
+isolation); duplicate REQUEST_CHANGES at an unchanged head is suppressed.
 """
 import os
 import unittest
@@ -15,7 +15,10 @@ import mcp_server
 HEAD_SHA = "a" * 40
 
 
-def _lock(mutations=None, correction=False):
+def _lock(mutations=None, correction=False, correction_pr=None):
+    mutations = list(mutations or [])
+    if correction and correction_pr is None and mutations:
+        correction_pr = mutations[-1].get("pr_number")
     return {
         "task": "review_pr",
         "remote": "prgs",
@@ -29,9 +32,11 @@ def _lock(mutations=None, correction=False):
         "ready_remote": None,
         "ready_org": None,
         "ready_repo": None,
-        "live_mutations": list(mutations or []),
+        "live_mutations": mutations,
         "correction_authorized": correction,
-        "correction_reason": None,
+        "correction_reason": "test" if correction else None,
+        "correction_pr_number": correction_pr if correction else None,
+        "correction_head_sha": None,
     }
 
 
@@ -64,25 +69,35 @@ class TestTerminalHardStopReasons(unittest.TestCase):
         self.assertEqual(
             mcp_server.terminal_review_hard_stop_reasons(5, "merge"), [])
 
-    def test_request_changes_blocks_everything(self):
+    def test_request_changes_blocks_same_pr_allows_other_pr_review(self):
         _seed([RC_A])
+        # Same PR: still hard-stopped for mark_ready/review/merge.
         for op in ("merge", "mark_ready", "review"):
-            for pr in (5, 6):
+            reasons = mcp_server.terminal_review_hard_stop_reasons(5, op)
-                reasons = mcp_server.terminal_review_hard_stop_reasons(pr, op)
+            self.assertTrue(reasons, f"{op}/5")
-                self.assertTrue(reasons, f"{op}/{pr}")
+            self.assertIn("request_changes on PR #5", reasons[0])
-                self.assertIn("request_changes on PR #5", reasons[0])
+            self.assertIn("#332", reasons[0])
-                self.assertIn("#332", reasons[0])
+        # #693: different PR may mark_ready / review (not merge via hard-stop alone).
+        self.assertEqual(
+            mcp_server.terminal_review_hard_stop_reasons(6, "mark_ready"), [])
+        self.assertEqual(
+            mcp_server.terminal_review_hard_stop_reasons(6, "review"), [])
+        # Merge of an unapproved other PR remains blocked by hard-stop path
+        # (last terminal is not approve of PR 6).
+        self.assertTrue(
+            mcp_server.terminal_review_hard_stop_reasons(6, "merge"))
 
-    def test_approve_allows_same_pr_merge_only(self):
+    def test_approve_allows_same_pr_merge_and_other_pr_review(self):
         _seed([APPROVED_A])
         self.assertEqual(
             mcp_server.terminal_review_hard_stop_reasons(5, "merge"), [])
         self.assertTrue(
             mcp_server.terminal_review_hard_stop_reasons(6, "merge"))
-        self.assertTrue(
+        # #693 cross-PR isolation: other PR formal review path is open.
-            mcp_server.terminal_review_hard_stop_reasons(6, "mark_ready"))
+        self.assertEqual(
-        self.assertTrue(
+            mcp_server.terminal_review_hard_stop_reasons(6, "mark_ready"), [])
-            mcp_server.terminal_review_hard_stop_reasons(6, "review"))
+        self.assertEqual(
+            mcp_server.terminal_review_hard_stop_reasons(6, "review"), [])
 
     def test_correction_reopens_review_path_only(self):
         _seed([RC_A], correction=True)
@@ -90,9 +105,11 @@ class TestTerminalHardStopReasons(unittest.TestCase):
             mcp_server.terminal_review_hard_stop_reasons(5, "mark_ready"), [])
         self.assertEqual(
             mcp_server.terminal_review_hard_stop_reasons(5, "review"), [])
-        # correction never opens a cross-PR merge
+        # scoped correction never opens a cross-PR merge
         self.assertTrue(
             mcp_server.terminal_review_hard_stop_reasons(6, "merge"))
+        # unscoped/cross-PR correction must not lift PR 6 via correction alone
+        # (PR 6 is allowed by isolation, not by correction scope)
 
 
 class TestMergeHardStopWiring(unittest.TestCase):
@@ -126,14 +143,29 @@ class TestMarkFinalHardStopWiring(unittest.TestCase):
         mcp_server._save_review_decision_lock(None)
         mcp_server.review_workflow_load.clear_review_workflow_load()
 
-    def test_mark_ready_blocked_after_terminal_mutation(self):
+    def test_mark_ready_same_pr_blocked_after_terminal_mutation(self):
         _seed([RC_A])
         result = mcp_server.gitea_mark_final_review_decision(
-            pr_number=6, action="approve", remote="prgs")
+            pr_number=5, action="approve", remote="prgs",
+            expected_head_sha=HEAD_SHA)
         self.assertFalse(result["marked_ready"])
         self.assertTrue(
             any("#332" in r for r in result["reasons"]), result["reasons"])
 
+    def test_mark_ready_other_pr_allowed_after_foreign_terminal(self):
+        """#693: foreign open-PR terminal must not block mark_final on PR B."""
+        _seed([RC_A])
+        no_lease = {"block": False, "reasons": [], "mutation_allowed": True}
+        with patch("mcp_server._list_pr_lease_comments", return_value=[]), \
+                patch("mcp_server._pr_work_lease_reviewer_block",
+                      return_value=no_lease), \
+                patch.object(mcp_server, "gitea_check_pr_eligibility",
+                             return_value={"head_sha": HEAD_SHA, "eligible": True}):
+            result = mcp_server.gitea_mark_final_review_decision(
+                pr_number=6, action="approve", remote="prgs",
+                expected_head_sha=HEAD_SHA)
+        self.assertTrue(result["marked_ready"], result.get("reasons"))
+
 
 def _feedback(blocking, stale=False, success=True):
     return {