fix(drain-proof): bind acknowledgement coverage to session identity (#661)

Review 582 (REQUEST_CHANGES at 95178349) found a residual fail-open of the
same class the PR set out to close. Acknowledgement coverage was decided by
comparing a count against a count:

    covers_live_sessions = live_count_known and acked_count >= sessions_live_other

Nothing bound an acknowledgement to the identity of a session that actually
owed one, so acknowledgements supplied for the requesting session and for a
session that does not exist satisfied the obligations of two live sessions
that never answered - minting a clean, correctly signed proof and an allow
verdict from the restart gate.

Coverage is now derived from authoritative impact-report evidence:

- New `_required_ack_sessions()` derives the required session ids from the
  report itself, via `ack_state` keys and/or `affected_sessions` filtered on
  `live and not is_requester`. The requester is excluded only on explicit
  `is_requester` evidence, never inferred.
- When both views are present they must name the same set, and the result is
  reconciled against `counts.sessions_live_other`. Missing, malformed,
  duplicated, contradictory, or unreconcilable identity evidence fails closed
  and outranks every permitting path, including the timeout policy.
- Coverage requires every required id to carry an explicit acknowledgement
  token keyed by that id. Acknowledgements for the requester, for unknown
  ids, or for fabricated ids never increase coverage.
- Caller-supplied acknowledgement cardinality is no longer proof of anything.

Failure propagates unchanged through `acks_or_timeout` -> `proof.clean` ->
`failed_checks` -> `gate_apply_restart` verdict `deny` / `allow=False`.

The earlier missing-acknowledgement remediation is preserved in full: absent,
None, non-mapping, empty, partial, stale, and unparseable acks still fail
closed, `ack_timeout_policy_applied` stays strict `value is True`, and the
legitimate zero-live-sessions and explicit-timeout paths still pass.

Reviewer's reproduction, before and after this commit:

    sessions_live_other = 2
    report ack_state    = {'other-0': 'pending', 'other-1': 'pending'}
    supplied acks       = {'req': 'ack', 'totally-bogus-session': 'ack'}

    before: acks_or_timeout = True  | proof.clean = True  | gate allow
    after:  acks_or_timeout = False | proof.clean = False | gate deny

Tests: 22 new cases in `AcknowledgementIdentityBindingTests` covering the
reviewer's exact exploit, wrong-ids-with-sufficient-count, partial identity
match, requester-only acks, fabricated ids, unproven per-session states,
missing/malformed/contradictory identity evidence, count mismatch, and the
preserved success paths.

Verification:
- `pytest tests/test_drain_proof.py` -> 61 passed, 56 subtests
  (baseline at 95178349: 39 passed, 26 subtests)
- Restart surface (6 modules) -> 154 passed, 68 subtests, exit 0
  (baseline at 95178349: 132 passed, 38 subtests)
- Full `pytest tests/` -> 5177 passed vs baseline 5155 passed; the 23
  failures are identical in both runs and pre-exist at 95178349.

Scope: drain_proof.py, tests/test_drain_proof.py.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01VRUZAf3Fr5n3kqhhiayN6C
(cherry picked from commit 4193b63f415b066ee292386c2c89bc3d2651a0cc)

allocator_service.py

@@ -133,10 +133,15 @@ ROLE_ACTIONS: dict[str, tuple[tuple[str, ...], tuple[str, ...]]] = {
 
 
 # Body phrases that prove an issue is an implementation container, not a
-# unit of direct author work (#844). Matched case-insensitively against the
-# issue body. Title alone is never sufficient (ordinary issues may mention
-# "epic" incidentally).
+# unit of direct author work (#844 / #854). Matched case-insensitively against
+# the issue body. Title alone is never sufficient (ordinary issues may mention
+# "epic", "roadmap", "vision", or "umbrella" incidentally).
+#
+# #854 extends the #844 marker set so product-vision (#652), phased-roadmap
+# (#653), and umbrella (#655) coordination records — which do not use the word
+# "epic" — are classified with the same semantic exclusion as epic containers.
 _CHILD_ONLY_BODY_MARKERS: tuple[str, ...] = (
+    # Epic / child-only (#844, live #631)
     "implementation is delivered via child issues only",
     "implementation is delivered through child issues only",
     "implementation is delivered via child issues",
@@ -150,9 +155,26 @@ _CHILD_ONLY_BODY_MARKERS: tuple[str, ...] = (
     "coordination container",
     "child-only container",
     "implementation is delegated to child",
+    # Vision / roadmap / umbrella coordination (#854, live #652/#653/#655).
+    # Prefer authoritative non-implementation / child-only scope language over
+    # bare words like "roadmap" so ordinary implementable issues that mention
+    # a parent vision or roadmap stay eligible.
+    "do not implement features on this issue",
+    "implementing features on this roadmap issue",
+    "implementation is via linked children only",
+    "no product feature claimed complete on this issue alone",
+    "phased delivery roadmap and epic sequencing",
+    "this issue is the enduring source of truth",
+    "enduring source of truth for the",
+    "canonical product vision — enduring source of truth",
+    "canonical product vision - enduring source of truth",
+    "state: vision-active",
+    "state: roadmap-active",
 )
 
-# Explicit epic / umbrella labels (structured evidence preferred over title).
+# Explicit epic / umbrella / vision / roadmap labels (structured evidence
+# preferred over title). Tracker alone is *not* included — ordinary issues
+# may carry a tracker label without being non-implementable containers.
 _EPIC_LABELS: frozenset[str] = frozenset(
     {
         "type:epic",
@@ -161,6 +183,16 @@ _EPIC_LABELS: frozenset[str] = frozenset(
         "scope:epic",
         "type:umbrella",
         "umbrella",
+        "kind:umbrella",
+        "scope:umbrella",
+        "type:vision",
+        "vision",
+        "kind:vision",
+        "scope:vision",
+        "type:roadmap",
+        "roadmap",
+        "kind:roadmap",
+        "scope:roadmap",
     }
 )
 
@@ -222,16 +254,45 @@ class WorkCandidate:
         }
 
 
+def _title_container_prefix(title_l: str) -> str | None:
+    """Return a coordination-title prefix token if *title_l* uses one (#854).
+
+    Title prefixes alone never exclude; they only corroborate body/label
+    evidence. Ordinary issues may say "roadmap" or "vision" mid-title.
+    """
+    for prefix, token in (
+        ("epic:", "title_epic_prefix"),
+        ("epic ", "title_epic_prefix"),
+        ("umbrella:", "title_umbrella_prefix"),
+        ("umbrella ", "title_umbrella_prefix"),
+        ("roadmap:", "title_roadmap_prefix"),
+        ("roadmap ", "title_roadmap_prefix"),
+        ("product vision:", "title_vision_prefix"),
+        ("product vision ", "title_vision_prefix"),
+        ("vision:", "title_vision_prefix"),
+        ("vision ", "title_vision_prefix"),
+    ):
+        if title_l.startswith(prefix):
+            return token
+    return None
+
+
 def classify_epic_or_child_only_container(
     c: WorkCandidate,
 ) -> tuple[bool, str | None]:
-    """Return whether *c* is an epic / child-only implementation container (#844).
+    """Return whether *c* is a non-implementable coordination container (#844/#854).
 
     Exclusion uses structured evidence first (labels, body scope language).
-    A bare title containing the word "epic" is **not** enough — ordinary
-    implementable issues may mention epics incidentally. A title that is
-    explicitly prefixed ``Epic:`` only counts when the body also proves
-    child-only / no-direct-implementation scope (or an epic label is present).
+    A bare title containing the words "epic", "roadmap", "vision", or
+    "umbrella" is **not** enough — ordinary implementable issues may mention
+    those terms incidentally. Explicit title prefixes (``Epic:``, ``Roadmap:``,
+    ``Product vision:``, ``Umbrella:``) only count when the body also proves
+    child-only / no-direct-implementation scope (or a container label is
+    present).
+
+    Covers epic, product-vision, phased-roadmap, umbrella, and child-only
+    records so the allocator never assigns coordination containers as direct
+    author work.
 
     PRs are never classified as containers here (they already have a head).
     """
@@ -245,25 +306,28 @@ def classify_epic_or_child_only_container(
     title_l = title.lower()
 
     body_hits = [m for m in _CHILD_ONLY_BODY_MARKERS if m in body_l]
-    title_epic_prefix = title_l.startswith("epic:") or title_l.startswith("epic ")
+    title_prefix = _title_container_prefix(title_l)
 
     if epic_label:
         detail = f"label={epic_label[0]}"
         if body_hits:
             detail = f"{detail}; body_marker={body_hits[0]!r}"
+        if title_prefix:
+            detail = f"{title_prefix}; {detail}"
         return True, detail
 
     if body_hits:
-        # Body proves child-only / umbrella scope. Title "Epic:" is corroborating
-        # but not required — containers without the word still exclude.
+        # Body proves child-only / vision / roadmap / umbrella scope. Title
+        # prefixes are corroborating but not required — containers without the
+        # title word still exclude.
         detail = f"body_marker={body_hits[0]!r}"
-        if title_epic_prefix:
-            detail = f"title_epic_prefix; {detail}"
+        if title_prefix:
+            detail = f"{title_prefix}; {detail}"
         return True, detail
 
-    # Title-only "Epic:" without body scope evidence is insufficient (#844 AC:
-    # eligibility does not rely solely on the word "Epic" in a title).
-    # Similarly, incidental "epic" mid-title without markers stays eligible.
+    # Title-only coordination prefix without body scope evidence is
+    # insufficient (#844/#854 AC: eligibility does not rely solely on a title
+    # word). Incidental mid-title mentions without markers stay eligible.
     return False, None
 
 

gitea_mcp_server.py

@@ -2068,6 +2068,7 @@ import lease_lifecycle  # noqa: E402
 import lease_policy  # noqa: E402
 import workflow_dashboard  # noqa: E402  # #605 live queue/lease dashboard
 import restart_coordinator  # noqa: E402  # #658 MCP restart coordinator/impact
+import drain_proof  # noqa: E402  # #661 pre-restart drain proof and hard gate
 import incident_bridge  # noqa: E402
 import sentry_observability  # noqa: E402  (#606 optional Sentry observability)
 import sentry_incident_bridge  # noqa: E402  (#607 Sentry→Gitea incident bridge)
@@ -22342,6 +22343,8 @@ def gitea_request_mcp_restart(
     request_override: bool = False,
     session_id: str | None = None,
     limit: int = 200,
+    drain_proof_json: str | None = None,
+    request_break_glass: bool = False,
 ) -> dict:
     """Evaluate a proposed MCP restart and return an impact preview (#658).
 
@@ -22351,10 +22354,15 @@ def gitea_request_mcp_restart(
     verdict, so the console (#642/#652) and operators can see what a restart
     would disrupt *before* any concurrent LLM work is destroyed.
 
-    This tool is **dry-run and never restarts anything.** The mutative apply
-    path is a separate child gated by a drain proof (non-goal here); calling
-    with ``dry_run=False`` still performs no restart and reports that apply is
-    not yet available.
+    This tool **never restarts a process.** In dry-run (the default) it returns
+    only the impact preview. With ``dry_run=False`` it enforces the #661 hard
+    gate: the apply request must present a valid, unexpired, clean drain proof
+    (``drain_proof_json``) or it is denied and a durable incident descriptor is
+    returned under ``incident``. Break-glass is the only bypass and is honoured
+    only when ``request_break_glass`` is set *and* the environment carries
+    ``GITEA_BREAKGLASS_RESTART_AUTHORIZATION``. Even an authorized gate performs
+    no restart here; actual execution is a further child. The gate outcome is
+    reported under ``apply_gate`` / ``apply_authorized``.
 
     Operator override authority is read from the process environment
     (``GITEA_OPERATOR_RESTART_OVERRIDE_AUTHORIZATION``), never self-asserted by
@@ -22473,12 +22481,54 @@ def gitea_request_mcp_restart(
     payload["requesting_session_id"] = sid
     payload["operator_override_requested"] = bool(request_override)
     payload["operator_override_authorized"] = operator_authorized
+    # Actual restart execution remains a further child; this tool never restarts
+    # a process. What #661 adds is the *hard gate*: an apply request (dry_run
+    # False) must present a valid, unexpired, clean drain proof, or it is denied
+    # and a durable incident is raised. Break-glass is the only bypass and its
+    # authorization is read from the environment, never self-asserted.
     payload["apply_supported"] = False
     if not dry_run:
-        payload["reasons"] = list(payload.get("reasons") or []) + [
-            "apply requested but not supported: sanctioned restart apply is "
-            "gated by a drain proof (separate child); no restart performed (#658)"
-        ]
+        proof_obj: dict | None = None
+        proof_parse_error: str | None = None
+        if drain_proof_json:
+            try:
+                parsed = json.loads(drain_proof_json)
+                proof_obj = parsed if isinstance(parsed, dict) else None
+                if proof_obj is None:
+                    proof_parse_error = "drain_proof_json is not a JSON object"
+            except (ValueError, TypeError) as exc:
+                proof_parse_error = f"invalid drain_proof_json: {_redact(str(exc))}"
+
+        break_glass_authorized = bool(
+            (
+                os.environ.get("GITEA_BREAKGLASS_RESTART_AUTHORIZATION") or ""
+            ).strip()
+        )
+        break_glass = bool(request_break_glass and break_glass_authorized)
+
+        expected_fp = drain_proof.impact_fingerprint(report.as_dict())
+        gate = drain_proof.gate_apply_restart(
+            proof=proof_obj,
+            break_glass=break_glass,
+            expected_impact_fingerprint=expected_fp,
+            requesting_session_id=sid,
+        )
+        gate_payload = gate.as_dict()
+        if proof_parse_error and not break_glass:
+            gate_payload["reasons"] = [proof_parse_error] + list(
+                gate_payload.get("reasons") or []
+            )
+        payload["apply_gate"] = gate_payload
+        payload["apply_authorized"] = gate.allow
+        payload["break_glass_requested"] = bool(request_break_glass)
+        payload["break_glass_authorized"] = break_glass_authorized
+        # Even an authorized gate performs no restart here: execution is a later
+        # child. The gate proves the apply path *would* be permitted.
+        payload["reasons"] = list(payload.get("reasons") or []) + list(
+            gate_payload.get("reasons") or []
+        )
+        if not gate.allow and gate.incident is not None:
+            payload["incident"] = gate.incident
     return payload
 
 

tests/test_drain_proof.py

@@ -0,0 +1,907 @@
+"""Tests for the pre-restart drain proof and hard gate (#661).
+
+Covers the acceptance criteria:
+
+1. Restart apply without a proof fails closed.
+2. A successful drain produces a verifiable proof.
+3. An open unsafe mutation makes the proof fail (multi-session fixture).
+4. Pass / fail / expired verification paths.
+
+Plus the security posture: forged/tampered proofs are rejected, break-glass is
+the only bypass and is never silent, a stale blast-radius fingerprint rejects a
+proof, and no per-process secret ever leaks into a serialized artifact.
+"""
+
+from __future__ import annotations
+
+import os
+import unittest
+from datetime import datetime, timedelta, timezone
+
+import drain_proof as dp
+import restart_coordinator as rc
+
+
+NOW = datetime(2026, 7, 24, 6, 0, 0, tzinfo=timezone.utc)
+SECRET = b"unit-test-drain-proof-secret-0123456789abcdef"
+
+
+def _live_pid() -> int:
+    return os.getpid()
+
+
+def _clean_drain_state() -> dict:
+    """Every drain action succeeded, no sessions outstanding."""
+
+    return {
+        "assignments_stopped": True,
+        "checkpoints_complete": True,
+        "handoffs_verified": True,
+        "leases_handled": True,
+        "acks": {},  # no other live sessions to acknowledge
+        "ack_timeout_policy_applied": False,
+    }
+
+
+def _safe_report() -> dict:
+    """Impact report with no other live work: a restart here is safe."""
+
+    report = rc.evaluate_restart_impact(
+        {"sessions": [], "leases": [], "inventory_complete": True},
+        now=NOW,
+        requesting_session_id="prgs-controller-1-req",
+    )
+    return report.as_dict()
+
+
+def _unsafe_mutation_report() -> dict:
+    """Multi-session report: a second session holds a live author mutation."""
+
+    sessions = [
+        {
+            "session_id": "prgs-controller-1-req",
+            "role": "controller",
+            "profile": "prgs-controller",
+            "pid": _live_pid(),
+            "status": "active",
+            "last_heartbeat_at": NOW.isoformat(),
+        },
+        {
+            "session_id": "prgs-author-99",
+            "role": "author",
+            "profile": "prgs-author",
+            "pid": _live_pid(),
+            "status": "active",
+            "last_heartbeat_at": NOW.isoformat(),
+        },
+    ]
+    leases = [
+        {
+            "lease_id": "lease-mut",
+            "session_id": "prgs-author-99",
+            "role": "author",
+            "phase": "implementing",
+            "work_kind": "issue",
+            "work_number": 661,
+            "worktree_path": "branches/issue-661",
+            "freshness": {"freshness": "active"},
+        }
+    ]
+    report = rc.evaluate_restart_impact(
+        {"sessions": sessions, "leases": leases, "inventory_complete": True},
+        now=NOW,
+        requesting_session_id="prgs-controller-1-req",
+    )
+    return report.as_dict()
+
+
+class BuildDrainProofTests(unittest.TestCase):
+    def test_clean_drain_produces_verifiable_clean_proof(self):
+        """AC#2: a successful drain produces a verifiable proof."""
+
+        proof = dp.build_drain_proof(
+            impact_report=_safe_report(),
+            drain_state=_clean_drain_state(),
+            requesting_session_id="prgs-controller-1-req",
+            now=NOW,
+            secret=SECRET,
+        )
+        self.assertTrue(proof.clean)
+        self.assertEqual(proof.failed_checks, [])
+        self.assertEqual(
+            {c.name for c in proof.checks}, set(dp.REQUIRED_CHECKS)
+        )
+        result = dp.verify_drain_proof(
+            proof.as_dict(), now=NOW, secret=SECRET
+        )
+        self.assertTrue(result.valid, result.reasons)
+        self.assertFalse(result.expired)
+        self.assertFalse(result.tampered)
+
+    def test_open_mutation_makes_proof_unclean(self):
+        """AC#3: an unsafe mutation still in flight fails the proof."""
+
+        proof = dp.build_drain_proof(
+            impact_report=_unsafe_mutation_report(),
+            drain_state=_clean_drain_state(),
+            now=NOW,
+            secret=SECRET,
+        )
+        self.assertFalse(proof.clean)
+        self.assertIn(dp.CHECK_NO_INFLIGHT_MUTATIONS, proof.failed_checks)
+        # Leases-handled also fails: the report still shows a disruptive lease.
+        self.assertIn(dp.CHECK_LEASES_HANDLED, proof.failed_checks)
+        result = dp.verify_drain_proof(proof.as_dict(), now=NOW, secret=SECRET)
+        self.assertFalse(result.valid)
+
+    def test_incomplete_inventory_fails_no_mutations_check(self):
+        proof = dp.build_drain_proof(
+            impact_report={"inventory_complete": False},
+            drain_state=_clean_drain_state(),
+            now=NOW,
+            secret=SECRET,
+        )
+        self.assertFalse(proof.clean)
+        self.assertIn(dp.CHECK_NO_INFLIGHT_MUTATIONS, proof.failed_checks)
+
+    def test_missing_checkpoint_flag_fails_closed(self):
+        state = _clean_drain_state()
+        del state["checkpoints_complete"]
+        proof = dp.build_drain_proof(
+            impact_report=_safe_report(), drain_state=state, now=NOW, secret=SECRET
+        )
+        self.assertFalse(proof.clean)
+        self.assertIn(dp.CHECK_CHECKPOINTS_COMPLETE, proof.failed_checks)
+
+    def test_non_true_flags_fail_closed(self):
+        """A truthy-but-not-True value (e.g. the string 'yes') must not pass."""
+
+        state = _clean_drain_state()
+        state["assignments_stopped"] = "yes"
+        proof = dp.build_drain_proof(
+            impact_report=_safe_report(), drain_state=state, now=NOW, secret=SECRET
+        )
+        self.assertIn(dp.CHECK_ASSIGNMENTS_STOPPED, proof.failed_checks)
+
+    def test_ack_timeout_policy_satisfies_ack_check(self):
+        state = _clean_drain_state()
+        state["acks"] = {"prgs-author-99": "pending"}
+        state["ack_timeout_policy_applied"] = True
+        proof = dp.build_drain_proof(
+            impact_report=_safe_report(), drain_state=state, now=NOW, secret=SECRET
+        )
+        names = {c.name: c.passed for c in proof.checks}
+        self.assertTrue(names[dp.CHECK_ACKS_OR_TIMEOUT])
+
+    def test_outstanding_acks_without_timeout_fail(self):
+        state = _clean_drain_state()
+        state["acks"] = {"prgs-author-99": "pending"}
+        state["ack_timeout_policy_applied"] = False
+        proof = dp.build_drain_proof(
+            impact_report=_safe_report(), drain_state=state, now=NOW, secret=SECRET
+        )
+        self.assertIn(dp.CHECK_ACKS_OR_TIMEOUT, proof.failed_checks)
+
+    def test_all_acked_satisfies_ack_check(self):
+        state = _clean_drain_state()
+        state["acks"] = {"prgs-author-99": "acked", "prgs-author-2": "acknowledged"}
+        proof = dp.build_drain_proof(
+            impact_report=_safe_report(), drain_state=state, now=NOW, secret=SECRET
+        )
+        names = {c.name: c.passed for c in proof.checks}
+        self.assertTrue(names[dp.CHECK_ACKS_OR_TIMEOUT])
+
+
+class VerifyDrainProofTests(unittest.TestCase):
+    def _clean_proof_dict(self) -> dict:
+        return dp.build_drain_proof(
+            impact_report=_safe_report(),
+            drain_state=_clean_drain_state(),
+            now=NOW,
+            secret=SECRET,
+        ).as_dict()
+
+    def test_missing_proof_is_invalid(self):
+        result = dp.verify_drain_proof(None, now=NOW, secret=SECRET)
+        self.assertFalse(result.valid)
+        self.assertIsNone(result.proof_id)
+
+    def test_expired_proof_is_invalid(self):
+        """AC#4: an expired proof fails verification."""
+
+        proof = self._clean_proof_dict()
+        later = NOW + timedelta(seconds=dp.DEFAULT_PROOF_TTL_SECONDS + 1)
+        result = dp.verify_drain_proof(proof, now=later, secret=SECRET)
+        self.assertFalse(result.valid)
+        self.assertTrue(result.expired)
+
+    def test_proof_valid_just_before_expiry(self):
+        proof = self._clean_proof_dict()
+        almost = NOW + timedelta(seconds=dp.DEFAULT_PROOF_TTL_SECONDS - 1)
+        result = dp.verify_drain_proof(proof, now=almost, secret=SECRET)
+        self.assertTrue(result.valid, result.reasons)
+
+    def test_wrong_secret_rejected(self):
+        """A proof minted in a prior process (different secret) will not verify."""
+
+        proof = self._clean_proof_dict()
+        result = dp.verify_drain_proof(proof, now=NOW, secret=b"other-secret")
+        self.assertFalse(result.valid)
+        self.assertTrue(result.tampered)
+
+    def test_flipping_clean_flag_is_detected(self):
+        """Forging clean=True on an unclean proof breaks the signature."""
+
+        unclean = dp.build_drain_proof(
+            impact_report=_unsafe_mutation_report(),
+            drain_state=_clean_drain_state(),
+            now=NOW,
+            secret=SECRET,
+        ).as_dict()
+        self.assertFalse(unclean["clean"])
+        unclean["clean"] = True  # forge
+        result = dp.verify_drain_proof(unclean, now=NOW, secret=SECRET)
+        self.assertFalse(result.valid)
+        self.assertTrue(result.tampered)
+
+    def test_tampering_a_check_is_detected(self):
+        unclean = dp.build_drain_proof(
+            impact_report=_unsafe_mutation_report(),
+            drain_state=_clean_drain_state(),
+            now=NOW,
+            secret=SECRET,
+        ).as_dict()
+        for c in unclean["checks"]:
+            if c["name"] == dp.CHECK_NO_INFLIGHT_MUTATIONS:
+                c["passed"] = True  # forge the failing check to pass
+        result = dp.verify_drain_proof(unclean, now=NOW, secret=SECRET)
+        self.assertFalse(result.valid)
+        self.assertTrue(result.tampered)
+
+    def test_missing_required_check_rejected(self):
+        proof = self._clean_proof_dict()
+        proof["checks"] = [
+            c for c in proof["checks"] if c["name"] != dp.CHECK_HANDOFFS_OK
+        ]
+        result = dp.verify_drain_proof(proof, now=NOW, secret=SECRET)
+        self.assertFalse(result.valid)
+
+    def test_stale_fingerprint_rejected(self):
+        proof = self._clean_proof_dict()
+        result = dp.verify_drain_proof(
+            proof,
+            now=NOW,
+            secret=SECRET,
+            expected_impact_fingerprint="deadbeef",
+        )
+        self.assertFalse(result.valid)
+
+    def test_matching_fingerprint_accepted(self):
+        report = _safe_report()
+        proof = dp.build_drain_proof(
+            impact_report=report,
+            drain_state=_clean_drain_state(),
+            now=NOW,
+            secret=SECRET,
+        ).as_dict()
+        fp = dp.impact_fingerprint(report)
+        result = dp.verify_drain_proof(
+            proof, now=NOW, secret=SECRET, expected_impact_fingerprint=fp
+        )
+        self.assertTrue(result.valid, result.reasons)
+
+
+class GateApplyRestartTests(unittest.TestCase):
+    def _clean_proof_dict(self) -> dict:
+        return dp.build_drain_proof(
+            impact_report=_safe_report(),
+            drain_state=_clean_drain_state(),
+            now=NOW,
+            secret=SECRET,
+        ).as_dict()
+
+    def test_apply_without_proof_denied(self):
+        """AC#1: restart apply without a proof fails closed + raises incident."""
+
+        decision = dp.gate_apply_restart(proof=None, now=NOW, secret=SECRET)
+        self.assertFalse(decision.allow)
+        self.assertEqual(decision.verdict, dp.GATE_DENY)
+        self.assertIsNotNone(decision.incident)
+        self.assertEqual(
+            decision.incident["kind"], "restart_drain_gate_denied"
+        )
+
+    def test_apply_with_valid_proof_allowed(self):
+        decision = dp.gate_apply_restart(
+            proof=self._clean_proof_dict(), now=NOW, secret=SECRET
+        )
+        self.assertTrue(decision.allow)
+        self.assertEqual(decision.verdict, dp.GATE_ALLOW)
+        self.assertIsNone(decision.incident)
+
+    def test_apply_with_expired_proof_denied_with_incident(self):
+        later = NOW + timedelta(seconds=dp.DEFAULT_PROOF_TTL_SECONDS + 5)
+        decision = dp.gate_apply_restart(
+            proof=self._clean_proof_dict(), now=later, secret=SECRET
+        )
+        self.assertFalse(decision.allow)
+        self.assertIsNotNone(decision.incident)
+
+    def test_apply_with_unclean_proof_denied(self):
+        """AC#3 at the gate: an unsafe-mutation proof is denied."""
+
+        unclean = dp.build_drain_proof(
+            impact_report=_unsafe_mutation_report(),
+            drain_state=_clean_drain_state(),
+            now=NOW,
+            secret=SECRET,
+        ).as_dict()
+        decision = dp.gate_apply_restart(proof=unclean, now=NOW, secret=SECRET)
+        self.assertFalse(decision.allow)
+        self.assertIsNotNone(decision.incident)
+
+    def test_break_glass_allows_without_proof_but_records_bypass(self):
+        decision = dp.gate_apply_restart(
+            proof=None, now=NOW, secret=SECRET, break_glass=True
+        )
+        self.assertTrue(decision.allow)
+        self.assertEqual(decision.verdict, dp.GATE_BREAK_GLASS)
+        self.assertTrue(decision.break_glass)
+        self.assertIsNone(decision.incident)
+        self.assertTrue(decision.audit_record["break_glass"])
+
+    def test_denied_gate_carries_stale_fingerprint_reason(self):
+        decision = dp.gate_apply_restart(
+            proof=self._clean_proof_dict(),
+            now=NOW,
+            secret=SECRET,
+            expected_impact_fingerprint="not-the-fingerprint",
+        )
+        self.assertFalse(decision.allow)
+
+
+class SecretHygieneTests(unittest.TestCase):
+    def test_secret_never_serialized(self):
+        proof = dp.build_drain_proof(
+            impact_report=_safe_report(),
+            drain_state=_clean_drain_state(),
+            now=NOW,
+            secret=SECRET,
+        )
+        blob = dp._canonical(proof.as_dict())
+        self.assertNotIn(SECRET.decode(), blob)
+        # The signature is a hex digest, not the raw secret.
+        self.assertNotIn(SECRET.hex(), blob)
+
+    def test_incident_descriptor_has_no_secret(self):
+        decision = dp.gate_apply_restart(proof=None, now=NOW, secret=SECRET)
+        blob = dp._canonical(decision.incident)
+        self.assertNotIn(SECRET.decode(), blob)
+
+
+def _drained_report_with_live_sessions(count: int) -> dict:
+    """Report with ``count`` other live sessions but nothing in flight.
+
+    Every other checklist item passes against this report, so a failure
+    isolates the acknowledgement check rather than tripping on mutations.
+    """
+
+    sessions = [
+        {
+            "session_id": "prgs-controller-1-req",
+            "role": "controller",
+            "profile": "prgs-controller",
+            "pid": _live_pid(),
+            "status": "active",
+            "last_heartbeat_at": NOW.isoformat(),
+        }
+    ]
+    for index in range(count):
+        sessions.append(
+            {
+                "session_id": f"prgs-author-{index}",
+                "role": "author",
+                "profile": "prgs-author",
+                "pid": _live_pid(),
+                "status": "active",
+                "last_heartbeat_at": NOW.isoformat(),
+            }
+        )
+    report = rc.evaluate_restart_impact(
+        {"sessions": sessions, "leases": [], "inventory_complete": True},
+        now=NOW,
+        requesting_session_id="prgs-controller-1-req",
+    )
+    return report.as_dict()
+
+
+class AcknowledgementFailClosedTests(unittest.TestCase):
+    """Acknowledgement evidence must fail closed unless explicitly verified.
+
+    Regression cover for the reviewed fail-open on PR #882: an absent ``acks``
+    key collapsed to ``{}`` and was read as "no other live sessions required to
+    acknowledge", so a proof minted clean and the restart gate allowed while the
+    impact report still showed other live sessions.
+    """
+
+    def _state(self, **overrides) -> dict:
+        state = _clean_drain_state()
+        state.pop("acks", None)
+        state["ack_timeout_policy_applied"] = False
+        state.update(overrides)
+        return state
+
+    def _acks_check(self, proof) -> dp.DrainCheck:
+        return next(c for c in proof.checks if c.name == dp.CHECK_ACKS_OR_TIMEOUT)
+
+    def _build(self, report: dict, state: dict):
+        return dp.build_drain_proof(
+            impact_report=report, drain_state=state, now=NOW, secret=SECRET
+        )
+
+    def assertAcksFailClosed(self, report: dict, state: dict) -> None:
+        proof = self._build(report, state)
+        self.assertFalse(self._acks_check(proof).passed)
+        self.assertIn(dp.CHECK_ACKS_OR_TIMEOUT, proof.failed_checks)
+        self.assertFalse(proof.clean)
+
+    # --- missing / null / empty / malformed ------------------------------
+
+    def test_missing_acks_key_with_live_sessions_fails_closed(self):
+        """The exact reviewed defect: absent key, three other live sessions."""
+        report = _drained_report_with_live_sessions(3)
+        self.assertEqual(report["counts"]["sessions_live_other"], 3)
+        state = self._state()
+        self.assertNotIn("acks", state)
+        proof = self._build(report, state)
+        check = self._acks_check(proof)
+        self.assertFalse(check.passed)
+        self.assertNotIn("no other live sessions", check.detail)
+        self.assertIn("fail closed", check.detail)
+        self.assertFalse(proof.clean)
+        self.assertEqual(proof.failed_checks, [dp.CHECK_ACKS_OR_TIMEOUT])
+
+    def test_none_acks_with_live_sessions_fails_closed(self):
+        self.assertAcksFailClosed(
+            _drained_report_with_live_sessions(2), self._state(acks=None)
+        )
+
+    def test_empty_acks_with_live_sessions_fails_closed(self):
+        self.assertAcksFailClosed(
+            _drained_report_with_live_sessions(1), self._state(acks={})
+        )
+
+    def test_malformed_acks_fail_closed(self):
+        for malformed in ([], "ack", 7, ("ack",), True):
+            with self.subTest(malformed=malformed):
+                self.assertAcksFailClosed(
+                    _drained_report_with_live_sessions(1),
+                    self._state(acks=malformed),
+                )
+
+    # --- stale / unproven values -----------------------------------------
+
+    def test_stale_or_unproven_ack_values_fail_closed(self):
+        for value in ("pending", "stale", "unknown", "", None, True, 1, NOW):
+            with self.subTest(value=value):
+                self.assertAcksFailClosed(
+                    _drained_report_with_live_sessions(1),
+                    self._state(acks={"prgs-author-0": value}),
+                )
+
+    def test_partial_coverage_fails_closed(self):
+        """Fewer acknowledgements than the report's live-session count."""
+        self.assertAcksFailClosed(
+            _drained_report_with_live_sessions(3),
+            self._state(acks={"prgs-author-0": "ack"}),
+        )
+
+    def test_one_unacked_entry_among_many_fails_closed(self):
+        self.assertAcksFailClosed(
+            _drained_report_with_live_sessions(2),
+            self._state(acks={"prgs-author-0": "ack", "prgs-author-1": "pending"}),
+        )
+
+    def test_unproven_live_session_count_fails_closed(self):
+        """A missing or malformed count cannot prove nobody had to acknowledge."""
+        malformed_counts = (
+            None,
+            {},
+            {"sessions_live_other": None},
+            {"sessions_live_other": "3"},
+            {"sessions_live_other": -1},
+            {"sessions_live_other": True},
+        )
+        for counts in malformed_counts:
+            with self.subTest(counts=counts):
+                report = _drained_report_with_live_sessions(0)
+                if counts is None:
+                    report.pop("counts", None)
+                else:
+                    report["counts"] = counts
+                self.assertAcksFailClosed(report, self._state())
+
+    # --- valid evidence still passes -------------------------------------
+
+    def test_complete_valid_acks_pass(self):
+        report = _drained_report_with_live_sessions(2)
+        state = self._state(
+            acks={"prgs-author-0": "ack", "prgs-author-1": "acknowledged"}
+        )
+        proof = self._build(report, state)
+        self.assertTrue(self._acks_check(proof).passed)
+        self.assertTrue(proof.clean)
+        self.assertEqual(proof.failed_checks, [])
+
+    def test_no_other_live_sessions_still_passes(self):
+        """Intended behavior retained: zero live sessions needs no acks."""
+        report = _drained_report_with_live_sessions(0)
+        self.assertEqual(report["counts"]["sessions_live_other"], 0)
+        proof = self._build(report, self._state())
+        check = self._acks_check(proof)
+        self.assertTrue(check.passed)
+        self.assertIn("sessions_live_other=0", check.detail)
+        self.assertTrue(proof.clean)
+
+    # --- timeout policy cannot become a second fail-open ------------------
+
+    def test_unproven_timeout_policy_cannot_open_the_gate(self):
+        for value in (None, "true", "yes", 1, "True", [], {}):
+            with self.subTest(value=value):
+                self.assertAcksFailClosed(
+                    _drained_report_with_live_sessions(2),
+                    self._state(ack_timeout_policy_applied=value),
+                )
+
+    def test_explicit_timeout_policy_permits(self):
+        proof = self._build(
+            _drained_report_with_live_sessions(2),
+            self._state(ack_timeout_policy_applied=True),
+        )
+        check = self._acks_check(proof)
+        self.assertTrue(check.passed)
+        self.assertIn("timeout policy", check.detail)
+        self.assertTrue(proof.clean)
+
+    # --- the gate itself must deny ---------------------------------------
+
+    def test_failed_ack_check_denies_the_restart_gate(self):
+        report = _drained_report_with_live_sessions(3)
+        proof = self._build(report, self._state())
+        self.assertFalse(proof.clean)
+        decision = dp.gate_apply_restart(
+            proof=proof.as_dict(),
+            now=NOW,
+            secret=SECRET,
+            expected_impact_fingerprint=dp.impact_fingerprint(report),
+        )
+        self.assertFalse(decision.allow)
+        self.assertEqual(decision.verdict, dp.GATE_DENY)
+        self.assertIsNotNone(decision.incident)
+
+    def test_unclean_ack_proof_fails_verification(self):
+        report = _drained_report_with_live_sessions(3)
+        proof = self._build(report, self._state())
+        result = dp.verify_drain_proof(
+            proof.as_dict(),
+            now=NOW,
+            secret=SECRET,
+            expected_impact_fingerprint=dp.impact_fingerprint(report),
+        )
+        self.assertFalse(result.valid)
+        self.assertFalse(result.clean)
+
+
+def _identity_report(*, requester: str, others: tuple[str, ...]) -> dict:
+    """Report with explicitly named requester and other live sessions.
+
+    Unlike :func:`_drained_report_with_live_sessions`, the session ids are
+    chosen by the caller so a test can supply acknowledgements for the *wrong*
+    identities while keeping the count correct.
+    """
+
+    sessions = [
+        {
+            "session_id": requester,
+            "role": "controller",
+            "profile": "prgs-controller",
+            "pid": _live_pid(),
+            "status": "active",
+            "last_heartbeat_at": NOW.isoformat(),
+        }
+    ]
+    for session_id in others:
+        sessions.append(
+            {
+                "session_id": session_id,
+                "role": "author",
+                "profile": "prgs-author",
+                "pid": _live_pid(),
+                "status": "active",
+                "last_heartbeat_at": NOW.isoformat(),
+            }
+        )
+    report = rc.evaluate_restart_impact(
+        {"sessions": sessions, "leases": [], "inventory_complete": True},
+        now=NOW,
+        requesting_session_id=requester,
+    )
+    return report.as_dict()
+
+
+class AcknowledgementIdentityBindingTests(unittest.TestCase):
+    """Acknowledgement coverage must be bound to session identity, not counted.
+
+    Regression cover for the second reviewed fail-open on PR #882 (review 582,
+    blocker B1): coverage compared ``acked_count`` against
+    ``counts.sessions_live_other``, so acknowledgements supplied for the
+    requesting session and for ids that do not exist satisfied the obligations
+    of the live sessions that never answered. The required identities are
+    carried by the report itself — ``ack_state`` keys and ``affected_sessions``
+    filtered on ``live and not is_requester`` — and only an acknowledgement
+    keyed by one of those ids may count for it.
+    """
+
+    def _state(self, **overrides) -> dict:
+        state = _clean_drain_state()
+        state.pop("acks", None)
+        state["ack_timeout_policy_applied"] = False
+        state.update(overrides)
+        return state
+
+    def _acks_check(self, proof) -> dp.DrainCheck:
+        return next(c for c in proof.checks if c.name == dp.CHECK_ACKS_OR_TIMEOUT)
+
+    def _build(self, report: dict, state: dict):
+        return dp.build_drain_proof(
+            impact_report=report, drain_state=state, now=NOW, secret=SECRET
+        )
+
+    def assertAcksFailClosed(self, report: dict, state: dict) -> dp.DrainCheck:
+        """Failure must propagate through the check, the proof, and the gate."""
+
+        proof = self._build(report, state)
+        check = self._acks_check(proof)
+        self.assertFalse(check.passed)
+        self.assertFalse(proof.clean)
+        self.assertIn(dp.CHECK_ACKS_OR_TIMEOUT, proof.failed_checks)
+        decision = dp.gate_apply_restart(
+            proof=proof.as_dict(),
+            now=NOW,
+            secret=SECRET,
+            expected_impact_fingerprint=dp.impact_fingerprint(report),
+        )
+        self.assertEqual(decision.verdict, dp.GATE_DENY)
+        self.assertFalse(decision.allow)
+        return check
+
+    # --- the reviewer's exact reproduction --------------------------------
+
+    def test_requester_plus_unknown_id_cannot_satisfy_two_live_sessions(self):
+        """Review 582 B1 verbatim: requester + a nonexistent session.
+
+        ``sessions_live_other=2`` with ``ack_state`` naming ``other-0`` and
+        ``other-1``; the drain state supplies an acknowledgement from the
+        requesting session itself and from a session that does not exist. The
+        count matches, the identities do not.
+        """
+
+        report = _identity_report(requester="req", others=("other-0", "other-1"))
+        self.assertEqual(report["counts"]["sessions_live_other"], 2)
+        self.assertEqual(
+            report["ack_state"], {"other-0": "pending", "other-1": "pending"}
+        )
+        state = self._state(acks={"req": "ack", "totally-bogus-session": "ack"})
+        check = self.assertAcksFailClosed(report, state)
+        self.assertIn("other-0", check.detail)
+        self.assertIn("other-1", check.detail)
+        self.assertIn("fail closed", check.detail)
+
+    # --- wrong / unknown / requester identities ---------------------------
+
+    def test_sufficient_count_of_wrong_ids_fails_closed(self):
+        """Right cardinality, wrong identities: two acks, neither required."""
+
+        report = _identity_report(requester="req", others=("other-0", "other-1"))
+        state = self._state(acks={"ghost-a": "ack", "ghost-b": "ack"})
+        check = self.assertAcksFailClosed(report, state)
+        self.assertIn("do not count", check.detail)
+
+    def test_more_acks_than_required_still_fails_on_wrong_ids(self):
+        """Coverage cannot be bought with volume: five acks, none required."""
+
+        report = _identity_report(requester="req", others=("other-0", "other-1"))
+        state = self._state(acks={f"ghost-{i}": "acknowledged" for i in range(5)})
+        self.assertAcksFailClosed(report, state)
+
+    def test_partial_identity_match_fails_closed(self):
+        """One required id acknowledged, the rest padded with unknown ids."""
+
+        report = _identity_report(
+            requester="req", others=("other-0", "other-1", "other-2")
+        )
+        state = self._state(
+            acks={"other-0": "ack", "ghost-1": "ack", "ghost-2": "ack"}
+        )
+        check = self.assertAcksFailClosed(report, state)
+        self.assertIn("other-1", check.detail)
+        self.assertIn("other-2", check.detail)
+
+    def test_requester_ack_never_satisfies_another_sessions_obligation(self):
+        """The requester is excluded from the required set and stays excluded."""
+
+        report = _identity_report(requester="req", others=("other-0",))
+        requester_rows = [s for s in report["affected_sessions"] if s["is_requester"]]
+        self.assertEqual([s["session_id"] for s in requester_rows], ["req"])
+        self.assertNotIn("req", report["ack_state"])
+        check = self.assertAcksFailClosed(report, self._state(acks={"req": "ack"}))
+        self.assertIn("other-0", check.detail)
+
+    def test_fabricated_ids_do_not_count_toward_coverage(self):
+        report = _identity_report(requester="req", others=("other-0",))
+        for bogus in ("", " ", "other-0 extra", "OTHER-0", "other-01", "0"):
+            with self.subTest(bogus=bogus):
+                self.assertAcksFailClosed(report, self._state(acks={bogus: "ack"}))
+
+    # --- per-session state must be explicitly valid ------------------------
+
+    def test_unproven_per_session_states_fail_closed(self):
+        """A required id present but not explicitly acknowledged fails closed."""
+
+        report = _identity_report(requester="req", others=("other-0", "other-1"))
+        for value in ("pending", "stale", "unknown", "", None, True, 1, NOW):
+            with self.subTest(value=value):
+                self.assertAcksFailClosed(
+                    report,
+                    self._state(acks={"other-0": "ack", "other-1": value}),
+                )
+
+    def test_report_ack_state_placeholder_is_never_read_as_an_ack(self):
+        """``ack_state`` values are the report's own placeholders, not evidence."""
+
+        report = _identity_report(requester="req", others=("other-0",))
+        report["ack_state"] = {"other-0": "ack"}
+        self.assertAcksFailClosed(report, self._state())
+
+    # --- missing / malformed / contradictory identity evidence -------------
+
+    def test_missing_identity_evidence_fails_closed(self):
+        report = _identity_report(requester="req", others=("other-0",))
+        report.pop("ack_state", None)
+        report.pop("affected_sessions", None)
+        check = self.assertAcksFailClosed(report, self._state(acks={"other-0": "ack"}))
+        self.assertIn("no session-identity evidence", check.detail)
+
+    def test_malformed_ack_state_fails_closed(self):
+        for malformed in ([], "other-0", 7, None, ("other-0",)):
+            with self.subTest(malformed=malformed):
+                report = _identity_report(requester="req", others=("other-0",))
+                report["ack_state"] = malformed
+                self.assertAcksFailClosed(
+                    report, self._state(acks={"other-0": "ack"})
+                )
+
+    def test_non_string_ack_state_key_fails_closed(self):
+        report = _identity_report(requester="req", others=("other-0",))
+        report["ack_state"] = {7: "pending"}
+        self.assertAcksFailClosed(report, self._state(acks={"other-0": "ack"}))
+
+    def test_malformed_affected_sessions_fails_closed(self):
+        for malformed in ("sessions", 7, {"session_id": "other-0"}, [None], [7]):
+            with self.subTest(malformed=malformed):
+                report = _identity_report(requester="req", others=("other-0",))
+                report.pop("ack_state", None)
+                report["affected_sessions"] = malformed
+                self.assertAcksFailClosed(
+                    report, self._state(acks={"other-0": "ack"})
+                )
+
+    def test_affected_sessions_without_explicit_booleans_fails_closed(self):
+        """``live``/``is_requester`` must be real booleans, never inferred."""
+
+        report = _identity_report(requester="req", others=("other-0",))
+        report.pop("ack_state", None)
+        for row in report["affected_sessions"]:
+            if row["session_id"] == "other-0":
+                row["is_requester"] = "false"
+        self.assertAcksFailClosed(report, self._state(acks={"other-0": "ack"}))
+
+    def test_affected_sessions_missing_live_flag_fails_closed(self):
+        report = _identity_report(requester="req", others=("other-0",))
+        report.pop("ack_state", None)
+        for row in report["affected_sessions"]:
+            row.pop("live", None)
+        self.assertAcksFailClosed(report, self._state(acks={"other-0": "ack"}))
+
+    def test_contradictory_ack_state_and_affected_sessions_fails_closed(self):
+        """Both views present and disagreeing is unresolvable, not a tie-break."""
+
+        report = _identity_report(requester="req", others=("other-0", "other-1"))
+        report["ack_state"] = {"other-0": "pending", "other-9": "pending"}
+        check = self.assertAcksFailClosed(
+            report, self._state(acks={"other-0": "ack", "other-9": "ack"})
+        )
+        self.assertIn("contradicts itself", check.detail)
+
+    def test_identity_count_mismatch_fails_closed(self):
+        """Identity evidence that cannot be reconciled with the count denies."""
+
+        report = _identity_report(requester="req", others=("other-0", "other-1"))
+        report["counts"] = dict(report["counts"], sessions_live_other=1)
+        check = self.assertAcksFailClosed(
+            report, self._state(acks={"other-0": "ack", "other-1": "ack"})
+        )
+        self.assertIn("cannot be reconciled", check.detail)
+
+    def test_broken_identity_evidence_outranks_timeout_policy(self):
+        """The sanctioned timeout path cannot paper over an unreadable report."""
+
+        report = _identity_report(requester="req", others=("other-0",))
+        report["ack_state"] = "not-a-mapping"
+        self.assertAcksFailClosed(report, self._state(ack_timeout_policy_applied=True))
+
+    # --- legitimate success is preserved -----------------------------------
+
+    def test_every_required_session_acknowledged_passes(self):
+        report = _identity_report(
+            requester="req", others=("other-0", "other-1", "other-2")
+        )
+        state = self._state(
+            acks={
+                "other-0": "ack",
+                "other-1": "acked",
+                "other-2": "acknowledged",
+            }
+        )
+        proof = self._build(report, state)
+        check = self._acks_check(proof)
+        self.assertTrue(check.passed)
+        self.assertTrue(proof.clean)
+        self.assertEqual(proof.failed_checks, [])
+        self.assertIn("acknowledged by identity", check.detail)
+        decision = dp.gate_apply_restart(
+            proof=proof.as_dict(),
+            now=NOW,
+            secret=SECRET,
+            expected_impact_fingerprint=dp.impact_fingerprint(report),
+        )
+        self.assertEqual(decision.verdict, dp.GATE_ALLOW)
+        self.assertTrue(decision.allow)
+
+    def test_required_session_ack_tolerates_surrounding_whitespace(self):
+        report = _identity_report(requester="req", others=("other-0",))
+        proof = self._build(report, self._state(acks={" other-0 ": " ACK "}))
+        self.assertTrue(self._acks_check(proof).passed)
+        self.assertTrue(proof.clean)
+
+    def test_no_other_live_sessions_still_passes_with_identity_evidence(self):
+        report = _identity_report(requester="req", others=())
+        self.assertEqual(report["counts"]["sessions_live_other"], 0)
+        self.assertEqual(report["ack_state"], {})
+        proof = self._build(report, self._state())
+        check = self._acks_check(proof)
+        self.assertTrue(check.passed)
+        self.assertIn("sessions_live_other=0", check.detail)
+        self.assertTrue(proof.clean)
+
+    def test_explicit_timeout_policy_retains_intended_behavior(self):
+        """Valid, correctly typed timeout evidence still permits the check."""
+
+        report = _identity_report(requester="req", others=("other-0", "other-1"))
+        proof = self._build(report, self._state(ack_timeout_policy_applied=True))
+        check = self._acks_check(proof)
+        self.assertTrue(check.passed)
+        self.assertIn("timeout policy", check.detail)
+        self.assertTrue(proof.clean)
+
+    def test_timeout_policy_still_strictly_typed_under_identity_binding(self):
+        report = _identity_report(requester="req", others=("other-0",))
+        for value in (None, "true", "True", 1, [], {}):
+            with self.subTest(value=value):
+                self.assertAcksFailClosed(
+                    report, self._state(ack_timeout_policy_applied=value)
+                )
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_issue_854_semantic_container_exclusion.py

@@ -0,0 +1,378 @@
+"""Allocator semantic container exclusion for vision/roadmap/umbrella (#854).
+
+#844 excluded epic / child-only containers (live #631) but product-vision
+(#652), phased-roadmap (#653), and umbrella (#655) coordination records still
+ranked as implementable work. This module is the live-equivalent canary:
+
+* #631 / #652 / #653 / #655-shaped records are all excluded in one inventory.
+* Independently executable children remain eligible and can be selected.
+* Ordinary issues that merely mention vision / roadmap / umbrella stay eligible.
+* Excluded containers never receive assignments or workflow leases.
+* Structured skip reason ``epic_or_child_only_container`` is reported.
+* Candidate-set fingerprint remains stable after exclusions.
+"""
+
+from __future__ import annotations
+
+import os
+import tempfile
+import unittest
+
+from allocator_service import (
+    OUTCOME_ASSIGNED,
+    OUTCOME_PREVIEW,
+    SKIP_EPIC_OR_CHILD_ONLY_CONTAINER,
+    WorkCandidate,
+    allocate_next_work,
+    candidate_set_fingerprint,
+    classify_epic_or_child_only_container,
+)
+from control_plane_db import ControlPlaneDB
+
+REMOTE = "prgs"
+ORG = "Scaled-Tech-Consulting"
+REPO = "Gitea-Tools"
+
+# Minimal bodies mirroring live coordination records (not full issue text).
+_EPIC_631_BODY = """
+## Scope (umbrella)
+
+This epic owns the **product roadmap and linkage** for the Web Console.
+Implementation is delivered via child issues only.
+
+## Explicit non-goals
+
+* Do not implement product features in this epic issue itself.
+* No product feature implementation is claimed complete solely on this epic.
+"""
+
+_VISION_652_BODY = """
+## Canonical product vision — enduring source of truth
+
+**This issue is the enduring source of truth for the MCP Control Plane Web Console product vision.**
+
+## Implementation linkage
+
+* **Do not implement features on this issue.**
+* Sequencing: roadmap issue + #631 children.
+
+## Canonical issue state
+
+```text
+STATE: vision-active
+WHO_IS_NEXT: controller (triage/ordering) / author (implementation of linked children only)
+```
+"""
+
+_ROADMAP_653_BODY = """
+## Purpose
+
+This issue is the **phased delivery roadmap and epic sequencing** for the MCP Control Plane Web Console.
+
+## Non-goals
+
+* Implementing features on this roadmap issue.
+* Deleting vision items by omitting them from phases without #652 change log.
+
+## Canonical issue state
+
+```text
+STATE: roadmap-active
+WHO_IS_NEXT: author
+```
+"""
+
+_UMBRELLA_655_BODY = """
+## Scope (umbrella)
+
+This issue owns the **canonical restart-governance program**. Implementation is via linked children only.
+
+## Acceptance criteria (umbrella)
+
+6. No product feature claimed complete on this issue alone.
+"""
+
+_CHILD_BODY = """
+## Problem
+
+Operators need a workflow-event timeline model for Phase 1.
+
+## Acceptance criteria
+
+- [ ] Timeline model API exists
+"""
+
+
+def _issue(
+    number: int,
+    *,
+    title: str = "",
+    body: str = "",
+    labels: tuple[str, ...] = ("status:ready", "type:feature"),
+    priority: int = 20,
+) -> WorkCandidate:
+    return WorkCandidate(
+        kind="issue",
+        number=number,
+        state="open",
+        labels=labels,
+        title=title or f"issue {number}",
+        body=body,
+        priority=priority,
+    )
+
+
+def _live_shaped_containers() -> list[WorkCandidate]:
+    return [
+        _issue(
+            631,
+            title="Epic: MCP Control Plane Web Console",
+            body=_EPIC_631_BODY,
+        ),
+        _issue(
+            652,
+            title="Product vision: MCP Control Plane Web Console (canonical)",
+            body=_VISION_652_BODY,
+        ),
+        _issue(
+            653,
+            title="Roadmap: MCP Control Plane Web Console (phased delivery)",
+            body=_ROADMAP_653_BODY,
+        ),
+        _issue(
+            655,
+            title="Umbrella: Governed MCP restart coordination and zero-disruption recovery",
+            body=_UMBRELLA_655_BODY,
+        ),
+    ]
+
+
+class ClassifySemanticContainersTest(unittest.TestCase):
+    def test_652_vision_is_container(self) -> None:
+        c = _issue(
+            652,
+            title="Product vision: MCP Control Plane Web Console (canonical)",
+            body=_VISION_652_BODY,
+        )
+        is_c, detail = classify_epic_or_child_only_container(c)
+        self.assertTrue(is_c)
+        self.assertIsNotNone(detail)
+        self.assertIn("body_marker", detail or "")
+
+    def test_653_roadmap_is_container(self) -> None:
+        c = _issue(
+            653,
+            title="Roadmap: MCP Control Plane Web Console (phased delivery)",
+            body=_ROADMAP_653_BODY,
+        )
+        is_c, detail = classify_epic_or_child_only_container(c)
+        self.assertTrue(is_c)
+        self.assertIn("body_marker", detail or "")
+
+    def test_655_umbrella_is_container(self) -> None:
+        c = _issue(
+            655,
+            title="Umbrella: Governed MCP restart coordination and zero-disruption recovery",
+            body=_UMBRELLA_655_BODY,
+        )
+        is_c, detail = classify_epic_or_child_only_container(c)
+        self.assertTrue(is_c)
+        self.assertIn("body_marker", detail or "")
+
+    def test_631_still_container_after_854(self) -> None:
+        c = _issue(
+            631,
+            title="Epic: MCP Control Plane Web Console",
+            body=_EPIC_631_BODY,
+        )
+        is_c, detail = classify_epic_or_child_only_container(c)
+        self.assertTrue(is_c)
+        self.assertIn("body_marker", detail or "")
+
+    def test_incidental_vision_roadmap_umbrella_words_not_container(self) -> None:
+        cases = (
+            (
+                "Document vision handoff conventions",
+                "Update docs so implementable issues that mention a vision "
+                "remain independently executable.",
+            ),
+            (
+                "Clarify roadmap sequencing notes",
+                "Write a short note about how the roadmap issue relates to children.",
+            ),
+            (
+                "Umbrella recovery checklist for authors",
+                "Authors should still implement the concrete recovery fix here.",
+            ),
+            (
+                "Product vision wording in the help text",
+                "Fix a typo in the operator-facing help string that says product vision.",
+            ),
+        )
+        for title, body in cases:
+            with self.subTest(title=title):
+                c = _issue(900, title=title, body=body)
+                is_c, detail = classify_epic_or_child_only_container(c)
+                self.assertFalse(is_c)
+                self.assertIsNone(detail)
+
+    def test_title_prefix_alone_not_container(self) -> None:
+        for title in (
+            "Epic: something mentioned only in title",
+            "Roadmap: title only without body scope",
+            "Product vision: title only without body scope",
+            "Umbrella: title only without body scope",
+        ):
+            with self.subTest(title=title):
+                c = _issue(
+                    901,
+                    title=title,
+                    body="Implement a concrete fix for the allocator skip list.",
+                )
+                is_c, detail = classify_epic_or_child_only_container(c)
+                self.assertFalse(is_c)
+                self.assertIsNone(detail)
+
+    def test_roadmap_label_alone_is_container(self) -> None:
+        c = _issue(
+            902,
+            title="Console delivery sequencing",
+            body="Track phased delivery only.",
+            labels=("status:ready", "type:roadmap"),
+        )
+        is_c, detail = classify_epic_or_child_only_container(c)
+        self.assertTrue(is_c)
+        self.assertIn("type:roadmap", detail or "")
+
+    def test_child_referencing_parent_policy_stays_eligible(self) -> None:
+        """Children may quote parent policy without becoming containers."""
+        c = _issue(
+            637,
+            title="Web Console: Workflow-event timeline model (Phase 1)",
+            body=(
+                _CHILD_BODY
+                + "\n\nParent #652 says do not implement on the vision issue; "
+                "this child is the implementable unit."
+            ),
+        )
+        is_c, _ = classify_epic_or_child_only_container(c)
+        self.assertFalse(is_c)
+
+
+class AllocateSemanticContainerExclusionTest(unittest.TestCase):
+    def setUp(self) -> None:
+        self._tmp = tempfile.TemporaryDirectory()
+        self.addCleanup(self._tmp.cleanup)
+        self.db = ControlPlaneDB(os.path.join(self._tmp.name, "cp.sqlite3"))
+
+    def _alloc(self, candidates, **kwargs):
+        defaults = dict(
+            session_id="sess-854",
+            role="author",
+            remote=REMOTE,
+            org=ORG,
+            repo=REPO,
+            profile_name="prgs-author",
+            username="jcwalker3",
+            claims={},
+            apply=False,
+        )
+        defaults.update(kwargs)
+        return allocate_next_work(self.db, candidates=candidates, **defaults)
+
+    def test_live_equivalent_canary_excludes_all_containers_selects_child(self) -> None:
+        containers = _live_shaped_containers()
+        child = _issue(
+            637,
+            title="Web Console: Workflow-event timeline model (Phase 1)",
+            body=_CHILD_BODY,
+        )
+        inventory = containers + [child]
+        res = self._alloc(inventory, apply=False)
+        self.assertTrue(res["success"], res)
+        self.assertEqual(res["outcome"], OUTCOME_PREVIEW)
+        self.assertEqual(res["selected"]["number"], 637)
+
+        skipped = {s["number"]: s for s in res["skipped"]}
+        for number in (631, 652, 653, 655):
+            self.assertIn(number, skipped, res["skipped"])
+            self.assertEqual(
+                skipped[number]["reason_code"],
+                SKIP_EPIC_OR_CHILD_ONLY_CONTAINER,
+            )
+            self.assertIn(
+                SKIP_EPIC_OR_CHILD_ONLY_CONTAINER, skipped[number]["reason"]
+            )
+
+    def test_containers_cannot_receive_assignment_or_lease(self) -> None:
+        containers = _live_shaped_containers()
+        res = self._alloc(containers, apply=True)
+        self.assertTrue(res["success"], res)
+        self.assertNotEqual(res["outcome"], OUTCOME_ASSIGNED)
+        self.assertIsNone(res.get("assignment"))
+        self.assertIsNone(res.get("selected"))
+        skipped = {s["number"]: s for s in res["skipped"]}
+        for number in (631, 652, 653, 655):
+            self.assertEqual(
+                skipped[number]["reason_code"],
+                SKIP_EPIC_OR_CHILD_ONLY_CONTAINER,
+            )
+
+        leases = []
+        if hasattr(self.db, "list_active_leases"):
+            leases = self.db.list_active_leases(
+                remote=REMOTE, org=ORG, repo=REPO
+            )
+        if not leases and hasattr(self.db, "list_leases"):
+            leases = self.db.list_leases(remote=REMOTE, org=ORG, repo=REPO)
+        for lease in leases or []:
+            work_number = (
+                lease.get("work_number") if isinstance(lease, dict) else None
+            )
+            self.assertNotIn(work_number, {631, 652, 653, 655})
+
+    def test_apply_selects_child_not_container(self) -> None:
+        containers = _live_shaped_containers()
+        child = _issue(
+            637,
+            title="Web Console: Workflow-event timeline model (Phase 1)",
+            body=_CHILD_BODY,
+        )
+        res = self._alloc(containers + [child], apply=True)
+        self.assertTrue(res["success"], res)
+        self.assertEqual(res["outcome"], OUTCOME_ASSIGNED)
+        self.assertEqual(res["selected"]["number"], 637)
+        self.assertEqual(res["assignment"]["work_number"], 637)
+
+    def test_fingerprint_stable_with_containers_present(self) -> None:
+        containers = _live_shaped_containers()
+        child = _issue(
+            637,
+            title="Web Console: Workflow-event timeline model (Phase 1)",
+            body=_CHILD_BODY,
+        )
+        inventory = containers + [child]
+        fp_before = candidate_set_fingerprint(inventory)
+        res = self._alloc(inventory, apply=False)
+        self.assertTrue(res["success"], res)
+        self.assertEqual(res["selected"]["number"], 637)
+        # Allocator reports the same CAS fingerprint for the full candidate set.
+        reported = res.get("candidate_set_fingerprint")
+        self.assertEqual(reported, fp_before)
+        # Re-fingerprint of the same inventory is byte-stable.
+        self.assertEqual(candidate_set_fingerprint(inventory), fp_before)
+
+    def test_incidental_mentions_remain_eligible(self) -> None:
+        ordinary = _issue(
+            700,
+            title="Document roadmap handoff conventions",
+            body="Write runbook text about vision vs roadmap vs child issues.",
+        )
+        res = self._alloc([ordinary], apply=False)
+        self.assertTrue(res["success"], res)
+        self.assertEqual(res["selected"]["number"], 700)
+        self.assertEqual(res["skipped"], [])
+
+
+if __name__ == "__main__":
+    unittest.main()