diff --git a/cloud/release_gate.py b/cloud/release_gate.py
new file mode 100644
index 0000000..6c64409
--- /dev/null
+++ b/cloud/release_gate.py
@@ -0,0 +1,203 @@
+"""Future release endpoint: the gate check, without the endpoint.
+
+This module is the wiring preparation for the release endpoint
+that PR #247 explicitly left open: ``release_blocked`` is returned
+alongside the merge response today, but nothing enforces it yet,
+because there is no server-side release endpoint in this codebase
+and ``deploy.py`` is an operator script, not a release endpoint
+(see ``docs/release-gate-and-ledger-anchor.md``).
+
+What this module IS:
+
+- A pure, read-only evaluator: ``evaluate_release`` re-reads the
+  hash chain through the SAME reader the merge endpoint uses
+  (``cloud/audit_wiring.pushback_block_for_task``) and ANDs it
+  with a FRESH hard-gate evaluation supplied by the caller. It
+  never appends to the chain, never calls ``AuthStore.audit``
+  (which writes a chain row in the same transaction), never
+  commits, and never deploys anything. Checking must not move
+  the chain head: otherwise the check itself would invalidate
+  the external anchor taken before it.
+- The contract the future endpoint must implement. The endpoint
+  itself (route, HTTP plumbing, task-status transition, actual
+  publication) is NOT built here: building a live endpoint in
+  this track would be exactly the "new live release endpoint
+  touching production" the task forbids. The endpoint, when it
+  is approved and built, calls this evaluator and maps its
+  decision to HTTP exactly as documented in the companion doc.
+
+What this module is NOT:
+
+- It is not a merge gate. Merge (``POST /tasks/{id}/merge``)
+  and release are separate decisions with separate re-checks:
+  a merge-time 200 is never a release pass. The future endpoint
+  must call this evaluator at release time, with fresh evidence,
+  even if the task was merged minutes ago.
+- It is not a deploy gate. ``deploy.py`` deploys the platform
+  itself (host release directory + unit restarts) and is
+  deliberately outside this gate; see the companion doc.
+- It does not decide task status, auth, or publication. Status
+  (``task_status``) and the hard-gate evidence (``hard_gate``)
+  are caller-supplied inputs, so the evaluator can be tested
+  without a server, a task row, or a publication step. When the
+  caller omits an input, the evaluator fails closed on that
+  input instead of assuming it (missing hard-gate evidence
+  blocks; an unmerged status blocks when a status is given).
+
+Decision shape (``evaluate_release`` return value)::
+
+    {
+        "allowed": bool,            # True only if every check passes
+        "http_status": 200 | 409,   # the status the endpoint maps to
+        "code": str,                # machine code, see below
+        "blocked_by": str | None,   # primary source, or None if allowed
+        "blocked_sources": [str],   # every applicable source, in order
+        "blocks": [str],            # hard-gate block codes, if any
+        "failed_checks": [str],     # audit-pushback failed checks, if any
+        "round": int | None,        # pushback round, if any
+        "modules": dict,            # per-module block detail, if any
+    }
+
+Machine codes (``code`` / ``blocked_sources``):
+
+- ``release_allowed`` -- every check passed.
+- ``release_requires_merged`` -- a task status was supplied and
+  it is not ``"merged"``. Release is a post-merge act; an
+  unmerged task has nothing to release.
+- ``release_blocked_state_unavailable`` -- the chain could not
+  be read at all (anything other than the reader's own
+  missing-table rule, which means "no chain has ever been
+  written" and is inherited from #247 unchanged). Fail-closed:
+  an unreadable chain is never read as "no block".
+- ``release_blocked_hard_gate`` -- the fresh hard-gate
+  evaluation (five checks: CI, directory, contract, coordinator,
+  reviews, plus branch protection) did not allow. The failing
+  codes travel in ``blocks`` verbatim, so the caller can tell
+  a hard-gate block from an audit block without parsing text.
+- ``release_blocked_audit_pushback`` -- the re-read chain says
+  a pushback is still open (``release_blocked`` from the same
+  reader the merge endpoint uses). This is the #247 reader's
+  verdict at release time, not a cached merge-time value.
+
+When several sources block at once, ``blocked_sources`` lists
+all of them (chain-unavailable dominates and short-circuits,
+because without a chain read no other verdict is trustworthy),
+while ``blocked_by``/``code`` name the first source in
+evaluation order: chain read, then task status, then hard gate,
+then audit pushback. The endpoint must return the full
+decision object, not just the first code, so an operator can
+see that fixing one source still leaves another blocking.
+
+CORRECTED-to-pass does NOT unblock (inherited, not invented):
+
+The reader already implements the #247/#244 resolved semantic:
+a meta-review correction to ``pass`` schedules a re-audit, it
+does not release the gate; only a fresh passing verdict or a
+passing re-reviewed pushback row unblocks. This evaluator adds
+no special case for corrections, so the release path cannot
+drift from the merge path: the same chain, read through the
+same reader, gives the same answer at both gates. The contract
+tests pin this: corrected-to-pass with no new passing
+conclusion stays blocked at release, exactly as at merge.
+"""
+
+from cloud.audit_wiring import pushback_block_for_task
+
+# Machine codes (kept as module constants so the future endpoint
+# and its tests spell them identically, never by string literal).
+CODE_ALLOWED = "release_allowed"
+CODE_REQUIRES_MERGED = "release_requires_merged"
+CODE_STATE_UNAVAILABLE = "release_blocked_state_unavailable"
+CODE_HARD_GATE = "release_blocked_hard_gate"
+CODE_AUDIT_PUSHBACK = "release_blocked_audit_pushback"
+CODE_HARD_GATE_EVIDENCE_MISSING = "release_hard_gate_evidence_missing"
+
+
+def _decision(allowed, code, blocked_by, sources, blocks=None,
+              failed_checks=None, round_no=None, modules=None):
+    return {
+        "allowed": allowed,
+        "http_status": 200 if allowed else 409,
+        "code": code,
+        "blocked_by": blocked_by,
+        "blocked_sources": list(sources),
+        "blocks": list(blocks or []),
+        "failed_checks": list(failed_checks or []),
+        "round": round_no,
+        "modules": dict(modules or {}),
+    }
+
+
+def evaluate_release(task_id, conn, hard_gate=None, task_status=None):
+    """Decide whether a task may be released, right now.
+
+    ``task_id`` is the task whose chain is re-read. ``conn`` is a
+    DB connection the caller owns (the evaluator never closes
+    it, never commits on it, never writes through it).
+    ``hard_gate`` must be a FRESH evaluation of the hard merge
+    gate (``cloud/merge_gate_hard.evaluate_hard_merge_gate``)
+    against fresh evidence: ``{"allowed": bool, "blocks": [...]}``.
+    Passing ``None`` blocks with
+    ``release_hard_gate_evidence_missing`` -- a merge-time 200,
+    a cached gate object, or "the task is already merged" is
+    never accepted as fresh evidence. ``task_status``, when
+    given, must be ``"merged"``; when omitted, the status check
+    is skipped and the caller owns it (the future endpoint must
+    not omit it).
+
+    Order: chain read first (unavailable short-circuits, because
+    every other verdict would be untrustworthy without it), then
+    task status, then hard gate, then audit pushback. Hard-gate
+    and pushback blocks are both collected, so a decision blocked
+    by both says so instead of hiding one behind the other.
+    """
+    # 1. Re-read the chain, now -- never a cached merge-time value.
+    # The reader itself returns "allow" when the audit_ledger
+    # table does not exist yet (no chain ever written, #247 rule,
+    # inherited unchanged). Any other read failure propagates
+    # out of the reader and is fail-closed here.
+    try:
+        pushback = pushback_block_for_task(conn, task_id)
+    except Exception:
+        return _decision(
+            False, CODE_STATE_UNAVAILABLE,
+            "audit_pushback_state_unavailable",
+            [CODE_STATE_UNAVAILABLE])
+    sources = []
+    blocks = []
+    failed_checks = []
+    round_no = None
+    modules = {}
+    primary_code = None
+    primary_by = None
+
+    def _note(code, by):
+        nonlocal primary_code, primary_by
+        sources.append(code)
+        if primary_code is None:
+            primary_code = code
+            primary_by = by
+
+    # 2. Task status, when the caller supplies it.
+    if task_status is not None and task_status != "merged":
+        _note(CODE_REQUIRES_MERGED, "task_status")
+
+    # 3. Fresh hard-gate evidence (five checks + protection).
+    if hard_gate is None:
+        _note(CODE_HARD_GATE_EVIDENCE_MISSING, "hard_gate")
+    elif not hard_gate.get("allowed"):
+        blocks = list(hard_gate.get("blocks") or [])
+        _note(CODE_HARD_GATE, "hard_gate")
+
+    # 4. Audit pushback, re-read above.
+    if pushback.get("release_blocked"):
+        failed_checks = list(pushback.get("failed_checks") or [])
+        round_no = pushback.get("round")
+        modules = dict(pushback.get("modules") or {})
+        _note(CODE_AUDIT_PUSHBACK, "audit_pushback")
+
+    if not sources:
+        return _decision(True, CODE_ALLOWED, None, [])
+    return _decision(False, primary_code, primary_by, sources,
+                     blocks=blocks, failed_checks=failed_checks,
+                     round_no=round_no, modules=modules)
diff --git a/cloud/tests/test_ledger_anchor_check.py b/cloud/tests/test_ledger_anchor_check.py
new file mode 100644
index 0000000..767bbfd
--- /dev/null
+++ b/cloud/tests/test_ledger_anchor_check.py
@@ -0,0 +1,152 @@
+"""Anchor script: exit-code contract for tools/ledger_anchor_check.py.
+
+Runs the script as a subprocess against throwaway SQLite chains
+in a TemporaryDirectory (deleted with the test). Pins only what
+the operator depends on: 0 pass, 1 verification failure with the
+failure named, 2 usage error, and --write-anchor refused on a
+failing chain. The script itself never writes the chain; the
+tamper/tail cases simulate privileged tampering by dropping the
+SQLite append-only triggers first (a normal UPDATE is already
+blocked by the trigger, which is itself asserted here).
+"""
+
+import json
+import os
+import sqlite3
+import subprocess
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parents[2]
+SCRIPT = REPO_ROOT / "tools" / "ledger_anchor_check.py"
+
+try:
+    from cloud.audit_wiring import record_audit_verdict
+    from cloud.ledger import LedgerStore
+except ImportError:
+    sys.path.insert(0, str(REPO_ROOT))
+    from cloud.audit_wiring import record_audit_verdict
+    from cloud.ledger import LedgerStore
+
+
+def _run(*args):
+    proc = subprocess.run(
+        [sys.executable, str(SCRIPT), *args],
+        capture_output=True, text=True, timeout=60)
+    try:
+        report = json.loads(proc.stdout) if proc.stdout.strip() else None
+    except ValueError:
+        report = None
+    return proc.returncode, report, proc.stderr
+
+
+class LedgerAnchorCheckTestCase(unittest.TestCase):
+    def setUp(self):
+        self.tmp = tempfile.TemporaryDirectory()
+        self.db_path = os.path.join(self.tmp.name, "control.db")
+        store = LedgerStore(self.db_path)
+        record_audit_verdict(store, "t1", "p1", "apps/web", "v2",
+                             "fail", "audit", failures=["ci_green"])
+        record_audit_verdict(store, "t1", "p1", "apps/web", "v2",
+                             "pass", "audit")
+        head = store.export()["head_hash"]
+        store.close()
+        self.anchor_path = os.path.join(self.tmp.name, "anchor.json")
+        with open(self.anchor_path, "w", encoding="utf-8") as handle:
+            json.dump({"version": 1, "head_hash": head, "count": 2},
+                      handle)
+
+    def tearDown(self):
+        self.tmp.cleanup()
+
+    def _copy_db(self, name):
+        import shutil
+        path = os.path.join(self.tmp.name, name)
+        shutil.copyfile(self.db_path, path)
+        return path
+
+    def test_pass_without_and_with_anchor(self):
+        code, report, _ = _run("--db", self.db_path)
+        self.assertEqual(code, 0)
+        self.assertTrue(report["ok"])
+        code, report, _ = _run("--db", self.db_path,
+                               "--anchor", self.anchor_path)
+        self.assertEqual(code, 0)
+        self.assertTrue(report["ok"])
+        self.assertEqual(report["head_advanced_by"], 0)
+
+    def test_normal_update_blocked_by_trigger_then_privileged_tamper_fails(self):
+        path = self._copy_db("tamper.db")
+        conn = sqlite3.connect(path)
+        with self.assertRaises(sqlite3.IntegrityError):
+            conn.execute(
+                "UPDATE audit_ledger SET detail='x' WHERE id=1")
+        conn.rollback()
+        conn.execute("DROP TRIGGER audit_ledger_no_update")
+        conn.execute("UPDATE audit_ledger SET detail='tampered'"
+                     " WHERE id=1")
+        conn.commit()
+        conn.close()
+        code, report, _ = _run("--db", path,
+                               "--anchor", self.anchor_path)
+        self.assertEqual(code, 1)
+        self.assertFalse(report["ok"])
+        self.assertTrue(any("entry_hash mismatch" in f
+                            for f in report["failures"]))
+
+    def test_tail_deletion_fails_against_old_anchor(self):
+        path = self._copy_db("tail.db")
+        conn = sqlite3.connect(path)
+        conn.execute("DROP TRIGGER audit_ledger_no_delete")
+        conn.execute("DELETE FROM audit_ledger WHERE id=2")
+        conn.commit()
+        conn.close()
+        code, report, _ = _run("--db", path,
+                               "--anchor", self.anchor_path)
+        self.assertEqual(code, 1)
+        self.assertFalse(report["ok"])
+        self.assertTrue(any("shorter than anchor" in f
+                            for f in report["failures"]))
+
+    def test_extended_chain_still_passes_anchor(self):
+        store = LedgerStore(self.db_path)
+        record_audit_verdict(store, "t1", "p1", "apps/web", "v2",
+                             "pass", "audit")
+        store.close()
+        code, report, _ = _run("--db", self.db_path,
+                               "--anchor", self.anchor_path)
+        self.assertEqual(code, 0)
+        self.assertTrue(report["ok"])
+        self.assertEqual(report["head_advanced_by"], 1)
+
+    def test_write_anchor_refused_on_failing_export(self):
+        path = self._copy_db("tail2.db")
+        conn = sqlite3.connect(path)
+        conn.execute("DROP TRIGGER audit_ledger_no_delete")
+        conn.execute("DELETE FROM audit_ledger WHERE id=2")
+        conn.commit()
+        conn.close()
+        store = LedgerStore(path)
+        export_path = os.path.join(self.tmp.name, "export.json")
+        with open(export_path, "w", encoding="utf-8") as handle:
+            json.dump(store.export(), handle)
+        store.close()
+        out_path = os.path.join(self.tmp.name, "new-anchor.json")
+        code, _report, _ = _run("--export", export_path,
+                                "--anchor", self.anchor_path,
+                                "--write-anchor", out_path)
+        self.assertEqual(code, 1)
+        self.assertFalse(os.path.exists(out_path))
+
+    def test_usage_errors_exit_2(self):
+        code, _report, _ = _run(
+            "--db", os.path.join(self.tmp.name, "nope.db"))
+        self.assertEqual(code, 2)
+        code, _report, _ = _run("--db", "postgres://host/db")
+        self.assertEqual(code, 2)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/cloud/tests/test_release_gate.py b/cloud/tests/test_release_gate.py
new file mode 100644
index 0000000..16ea325
--- /dev/null
+++ b/cloud/tests/test_release_gate.py
@@ -0,0 +1,268 @@
+"""Future release endpoint: contract tests for cloud/release_gate.
+
+These tests pin the CONTRACT, not an endpoint: there is no live
+release endpoint in this codebase (building one here would be
+the "new live endpoint touching production" this track forbids),
+so every test calls ``evaluate_release`` directly with a local
+SQLite chain. Nothing here deploys, publishes, or touches a
+production flow; the chain lives in a TemporaryDirectory and is
+deleted with the test.
+
+What is pinned (and nowhere else):
+
+- A blocked audit pushback blocks release (409, audit code),
+  even when the fresh hard gate passes.
+- A passing re-audit unblocks release -- but only with a FRESH
+  passing hard gate supplied by the caller; a merge-time 200 is
+  never an input, and a missing hard gate blocks fail-closed.
+- A chain-read failure blocks fail-closed (state unavailable),
+  distinguishable from an audit block and from a hard-gate block.
+- A hard-gate failure blocks release even when the chain is
+  clear, and both sources are listed when both block.
+- CORRECTED-to-pass does NOT unblock: a meta-review correction
+  to ``pass`` with no new passing conclusion stays blocked; only
+  a fresh passing verdict unblocks (the #247/#244 semantic,
+  re-checked at release time through the same reader).
+- A fix alone does not unblock.
+- A merge-time pass is not reused: a chain that was clear at
+  "merge time" and is blocked by the time release is evaluated
+  blocks release (the evaluator re-reads the chain every call).
+- The evaluator is read-only: evaluating never moves the chain
+  head (no row is appended by a check).
+"""
+
+import os
+import sqlite3
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+
+try:
+    from cloud.audit_pushback import GATE_CHECKS  # noqa: F401
+    from cloud.audit_wiring import pushback_package_from_gate
+    from cloud.audit_wiring import record_audit_verdict
+    from cloud.audit_wiring import record_fix
+    from cloud.audit_wiring import record_meta_review
+    from cloud.audit_wiring import record_pushback
+    from cloud.audit_wiring import record_reaudit
+    from cloud.ledger import LedgerStore
+    from cloud.merge_gate_hard import evaluate_hard_merge_gate
+    from cloud.release_gate import evaluate_release
+except ImportError:
+    sys.path.insert(0, str(Path(__file__).resolve().parents[2]))
+    from cloud.audit_pushback import GATE_CHECKS  # noqa: F401
+    from cloud.audit_wiring import pushback_package_from_gate
+    from cloud.audit_wiring import record_audit_verdict
+    from cloud.audit_wiring import record_fix
+    from cloud.audit_wiring import record_meta_review
+    from cloud.audit_wiring import record_pushback
+    from cloud.audit_wiring import record_reaudit
+    from cloud.ledger import LedgerStore
+    from cloud.merge_gate_hard import evaluate_hard_merge_gate
+    from cloud.release_gate import evaluate_release
+
+MODULE = "apps/web"
+CONTRACT = "v2"
+
+
+def _passing_gate():
+    return evaluate_hard_merge_gate(
+        files_changed=["apps/web/a.py"], owned_dir="apps/web",
+        protection="protected", ci_status="success",
+        ci_checks=[{"name": "ci", "status": "success"}],
+        required_checks=["ci"], contract_version="v2",
+        contract_frozen=True, coordinator_approved=True,
+        unresolved_review_comments=0)
+
+
+def _failing_gate():
+    return evaluate_hard_merge_gate(
+        files_changed=["apps/web/a.py"], owned_dir="apps/web",
+        protection="protected", ci_status="pending",
+        ci_checks=[{"name": "ci", "status": "pending"}],
+        required_checks=["ci"], contract_version="v2",
+        contract_frozen=True, coordinator_approved=True,
+        unresolved_review_comments=0)
+
+
+class ReleaseGateTestCase(unittest.TestCase):
+    def setUp(self):
+        self.tmp = tempfile.TemporaryDirectory()
+        self.db_path = os.path.join(self.tmp.name, "control.db")
+        self.store = LedgerStore(self.db_path)
+        self.task = "task-1"
+        self.project = "proj-1"
+
+    def tearDown(self):
+        try:
+            self.store.close()
+        except Exception:
+            pass
+        self.tmp.cleanup()
+
+    def _conn(self):
+        return sqlite3.connect(self.db_path)
+
+    def _decide(self, hard_gate=None, task_status="merged"):
+        conn = self._conn()
+        try:
+            return evaluate_release(
+                self.task, conn, hard_gate=hard_gate,
+                task_status=task_status)
+        finally:
+            conn.close()
+
+    def _block_task(self):
+        record_audit_verdict(
+            self.store, self.task, self.project, MODULE, CONTRACT,
+            "fail", "audit", failures=["ci_green"])
+        package = pushback_package_from_gate(
+            _failing_gate(), self.task, 0)
+        record_pushback(self.store, self.task, self.project, MODULE,
+                        CONTRACT, 1, package["failed_checks"], package,
+                        failure_source="audit")
+        return package
+
+    def _head(self):
+        return self.store.verify()["head_hash"]
+
+    def test_audit_pushback_blocks_release_even_with_passing_gate(self):
+        self._block_task()
+        decision = self._decide(hard_gate=_passing_gate())
+        self.assertFalse(decision["allowed"])
+        self.assertEqual(decision["http_status"], 409)
+        self.assertEqual(decision["code"],
+                         "release_blocked_audit_pushback")
+        self.assertEqual(decision["blocked_by"], "audit_pushback")
+        self.assertIn("release_blocked_audit_pushback",
+                      decision["blocked_sources"])
+        self.assertIn("ci_green", decision["failed_checks"])
+        self.assertEqual(decision["round"], 1)
+
+    def test_reaudit_pass_allows_release_with_fresh_passing_gate(self):
+        package = self._block_task()
+        record_reaudit(self.store, self.task, self.project, MODULE,
+                       CONTRACT, 1, {"verdict": "pass"},
+                       package=package)
+        decision = self._decide(hard_gate=_passing_gate())
+        self.assertTrue(decision["allowed"])
+        self.assertEqual(decision["http_status"], 200)
+        self.assertEqual(decision["code"], "release_allowed")
+        self.assertIsNone(decision["blocked_by"])
+        self.assertEqual(decision["blocked_sources"], [])
+
+    def test_corrected_to_pass_still_blocks_until_fresh_pass(self):
+        # One failing verdict is the ONLY block here, so the
+        # correction below is the only thing that could unblock
+        # -- if it did, this test would catch it. (A second fail
+        # or an open pushback would mask a wrong unblock.)
+        verdict = record_audit_verdict(
+            self.store, self.task, self.project, MODULE, CONTRACT,
+            "fail", "audit", failures=["ci_green"])
+        self.assertFalse(
+            self._decide(hard_gate=_passing_gate())["allowed"])
+        # Audit-of-audit correction: the original fail was wrong,
+        # corrected to pass. That schedules a re-audit; it does
+        # NOT release the gate by itself.
+        record_meta_review(
+            self.store, self.task, self.project, MODULE, CONTRACT,
+            verdict["id"], "fail", "pass", True, reviewer="auditor-b")
+        decision = self._decide(hard_gate=_passing_gate())
+        self.assertFalse(decision["allowed"])
+        self.assertEqual(decision["code"],
+                         "release_blocked_audit_pushback")
+        # Only a fresh passing verdict unblocks.
+        record_audit_verdict(
+            self.store, self.task, self.project, MODULE, CONTRACT,
+            "pass", "audit")
+        decision = self._decide(hard_gate=_passing_gate())
+        self.assertTrue(decision["allowed"], decision)
+
+    def test_hard_gate_blocks_release_when_chain_is_clear(self):
+        record_audit_verdict(
+            self.store, self.task, self.project, MODULE, CONTRACT,
+            "pass", "audit")
+        decision = self._decide(hard_gate=_failing_gate())
+        self.assertFalse(decision["allowed"])
+        self.assertEqual(decision["http_status"], 409)
+        self.assertEqual(decision["code"], "release_blocked_hard_gate")
+        self.assertEqual(decision["blocked_by"], "hard_gate")
+        self.assertTrue(decision["blocks"])
+        self.assertNotIn("release_blocked_audit_pushback",
+                         decision["blocked_sources"])
+
+    def test_both_sources_listed_when_both_block(self):
+        self._block_task()
+        decision = self._decide(hard_gate=_failing_gate())
+        self.assertFalse(decision["allowed"])
+        self.assertIn("release_blocked_hard_gate",
+                      decision["blocked_sources"])
+        self.assertIn("release_blocked_audit_pushback",
+                      decision["blocked_sources"])
+        self.assertTrue(decision["blocks"])
+        self.assertTrue(decision["failed_checks"])
+
+    def test_chain_read_failure_fails_closed(self):
+        conn = self._conn()
+        conn.close()
+        decision = evaluate_release(
+            self.task, conn, hard_gate=_passing_gate(),
+            task_status="merged")
+        self.assertFalse(decision["allowed"])
+        self.assertEqual(decision["http_status"], 409)
+        self.assertEqual(decision["code"],
+                         "release_blocked_state_unavailable")
+        self.assertEqual(
+            decision["blocked_by"],
+            "audit_pushback_state_unavailable")
+
+    def test_missing_hard_gate_evidence_blocks(self):
+        record_audit_verdict(
+            self.store, self.task, self.project, MODULE, CONTRACT,
+            "pass", "audit")
+        decision = self._decide(hard_gate=None)
+        self.assertFalse(decision["allowed"])
+        self.assertEqual(decision["code"],
+                         "release_hard_gate_evidence_missing")
+
+    def test_unmerged_task_cannot_release(self):
+        record_audit_verdict(
+            self.store, self.task, self.project, MODULE, CONTRACT,
+            "pass", "audit")
+        decision = self._decide(hard_gate=_passing_gate(),
+                                task_status="completed")
+        self.assertFalse(decision["allowed"])
+        self.assertEqual(decision["code"], "release_requires_merged")
+
+    def test_merge_time_pass_is_not_reused_at_release(self):
+        # "Merge time": chain clear, fresh gate passes.
+        first = self._decide(hard_gate=_passing_gate())
+        self.assertTrue(first["allowed"], first)
+        # Between merge and release, a pushback lands on the chain.
+        self._block_task()
+        second = self._decide(hard_gate=_passing_gate())
+        self.assertFalse(second["allowed"])
+        self.assertEqual(second["code"],
+                         "release_blocked_audit_pushback")
+
+    def test_fix_alone_does_not_unblock_release(self):
+        package = self._block_task()
+        record_fix(self.store, self.task, self.project, MODULE,
+                   CONTRACT, 1,
+                   {"summary": "fix ci", "diff_sha256": "b" * 64,
+                    "files_changed": ["apps/web/a.py"]}, package)
+        decision = self._decide(hard_gate=_passing_gate())
+        self.assertFalse(decision["allowed"])
+
+    def test_evaluator_is_read_only(self):
+        self._block_task()
+        before = self._head()
+        self._decide(hard_gate=_passing_gate())
+        self._decide(hard_gate=_failing_gate())
+        self.assertEqual(self._head(), before)
+        self.assertTrue(self.store.verify()["ok"])
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/docs/release-gate-and-ledger-anchor.md b/docs/release-gate-and-ledger-anchor.md
new file mode 100644
index 0000000..745996c
--- /dev/null
+++ b/docs/release-gate-and-ledger-anchor.md
@@ -0,0 +1,401 @@
+# 发布端点接线准备 + 账本锚点运维流程
+
+> 本轨性质：**接线准备，不是发布端点本身**。本轨不新建 live
+> 发布端点、不碰生产、不跑 `deploy.py`、不合并、不部署。
+> 发布端点是否立项、锚点存哪里、校验周期多长，均属用户侧
+> 拍板项（见 §6），本文只给推荐值与判断依据，不替用户定。
+>
+> 基底：堆叠于 PR #247（`feat-audit-wiring`，`217a27f`），
+> 合并顺序：#209 → #240 → #244 → #241 → #247 → 本轨。
+> 本轨代码：`cloud/release_gate.py`（纯只读 evaluator）、
+> `cloud/tests/test_release_gate.py`（11 项契约测试）、
+> `tools/ledger_anchor_check.py`（只读校验脚本）、
+> `cloud/tests/test_ledger_anchor_check.py`（脚本退出码测试）。
+> 本轨不改 #247 / #241 / #244 / #240 / #209 的任何语义：
+> 硬门禁五项、推回阻塞、CORRECTED-to-pass 不解封、链
+> fail-closed 规则，全部沿用，本文只说明它们在发布时
+> 如何被**重新**执行。
+
+## 1. 现状缺口（#247 留下的原话）
+
+- 合并端点 `POST /tasks/{id}/merge` 已在链上推回阻塞与硬门禁
+  五项之间做 AND：任一阻塞即 409、状态不变，并在响应里附
+  `audit_pushback` 对象（`merge_blocked` / `release_blocked` /
+  `blocked_by="audit_pushback"` / `round` / `failed_checks`）。
+- 但本仓库**没有独立的发布端点**：`release_blocked` 今天只是
+  随合并响应返回的一个字段，由“未来的发布端点用同一 reader
+  强制”。在那之前，合并放行后、发布前没有任何服务端检查
+  会再读一次链。
+- 账本（#241）已有导出头哈希，但**没有库外锚点存放与定期
+  校验的运维流程**：头哈希只在导出响应里出现一次，不存下来
+  就等于没有锚点；尾巴删除单靠库内校验发现不了（#241 已明
+  说），必须靠“旧锚点 vs 当前链”的比对。
+
+## 2. 未来发布端点接口契约（建议，待立项后实现）
+
+### 2.1 端点
+
+| 项 | 建议值 | 说明 |
+|---|---|---|
+| 方法 + 路径 | `POST /tasks/{id}/release` | 与 `POST /tasks/{id}/merge` 对仗；`{id}` 为任务 id，路径风格与现有任务端点一致 |
+| 请求体 | `{}` 或 `{"confirm": true}`（二选一，立项时定） | 本轨不规定体字段；关键在服务端**不信任**体里的任何门禁结论，只信任自己重算的结果 |
+| 成功 | `200` + 任务对象 + `release_gate` 决策对象 | 决策对象即 `evaluate_release` 的返回值原样返回，不另起一套字段 |
+| 阻塞 | `409` + `{"error": "release blocked", "release_gate": {...}}` | 见 §2.4 的阻塞码；阻塞时**不改任务状态、不发布、不写链** |
+| 任务不存在 | `404` | 与 merge 端点一致 |
+| 无权 | `403` | 见 §2.2 |
+
+本轨**没有实现这个端点**：`cloud/release_gate.py` 只有 evaluator，
+没有路由、没有 HTTP  plumbing、没有任务状态变更、没有发布动作。
+契约测试直接测 evaluator（见 §4），不测一个不存在的端点。
+
+### 2.2 鉴权：与 verify/export 同源、但为写动作
+
+- 身份来源与 `GET /admin/audit-ledger/verify`、
+  `GET /admin/audit-ledger/export` **一致**：只认环境变量
+  `CODEX_GLOBAL_ADMINS`（`_is_global_admin`），未配置即全体
+  403 fail-closed，绝不回落到项目角色推导。
+- 但动作性质**不一致**：verify/export 是全局管理员**只读**；
+  发布是**写动作**（对外发布），所以发布端点必须是
+  “全局管理员写”，不能是“全局管理员只读”，更不能只凭
+  项目 `approve_merge`（合并权）就放行发布。合并与发布是
+  两道不同的授权：项目 maintainer 能合并不等于能发布全系统。
+- 被拒（403）的审计口径沿用现有 `_audit_admin` 惯例（成功与
+  被拒都记；注意 `AuthStore.audit` 会同事务写链，见 §2.5 的
+  头移动说明）。409 阻塞本身**不写审计**：阻塞只是只读检查
+  的结果，每次被拒查询都写链会无意义地移动链头、污染锚点。
+
+### 2.3 接线点：发布前必做的三件事（顺序即 §3 的求值顺序）
+
+未来端点在执行任何发布动作之前，必须按顺序做：
+
+1. **重读链**：调 `evaluate_release`，它内部调
+   `cloud/audit_wiring.pushback_block_for_task`（与 merge 端点
+   同一个 reader）。读到的必须是**发布时刻**的链状态。
+2. **重算硬门禁**：用**发布时刻的新证据**重新跑
+   `evaluate_hard_merge_gate`（CI、目录、合同、协调员、评审、
+   分支保护五项 + 保护），把结果传给 evaluator。合并时的
+   gate 对象、合并时的 200，一律不作输入。
+3. **核任务状态**：任务状态须为 `merged` 才可发布（evaluator
+   的 `task_status` 参数；端点不得省略它）。
+
+三件缺一即 fail-closed：链读不到 → 409；硬门禁证据缺失 →
+409；状态不是 `merged` → 409。发布动作只在 evaluator 返回
+`allowed=true` 后执行，且发布动作本身的成功记录（如需记账）
+必须是**显式的新动作**，不是检查的副产品。
+
+### 2.4 阻塞源区分（错误码与阻塞码对照）
+
+`release_gate` 决策对象同时返回 `code`（首要阻塞码）、
+`blocked_by`（首要阻塞源）、`blocked_sources`（全部阻塞源），
+端点必须原样返回整个对象，不能只返回首要码——否则修好
+一个源后才发现另一个源仍阻塞，运维会被误导。
+
+| 阻塞源 | `code` | `blocked_by` | HTTP | 附加字段 | 修复路径 |
+|---|---|---|---|---|---|
+| 链读失败 fail-closed | `release_blocked_state_unavailable` | `audit_pushback_state_unavailable` | 409 | 无（读不到即无可信细节） | 修读链通路（DB/权限），重调；绝不能“先放行、后补查” |
+| 任务未合并 | `release_requires_merged` | `task_status` | 409 | — | 先走合并流程到 `merged` |
+| 硬门禁五项失败 | `release_blocked_hard_gate` | `hard_gate` | 409 | `blocks`（硬门禁码原样，如 `ci_not_green`） | 补齐五项证据后重调；与 merge 的 blocks 码同一套，不解析文本 |
+| 审计推回阻塞 | `release_blocked_audit_pushback` | `audit_pushback` | 409 | `failed_checks`、`round`、`modules`（与 merge 响应里的 `audit_pushback` 对象同源） | 修问题 → 重审通过（见 §2.6），重调 |
+| 硬门禁证据缺失 | `release_hard_gate_evidence_missing` | `hard_gate` | 409 | — | 调用方必须提交发布时刻的新证据；这不是“证据不足放行”，是直接阻塞 |
+
+例外（沿用 #247，不扩大）：`audit_ledger` 表根本不存在时，
+reader 返回“无推回状态”（链从未写过），不算读链失败。
+这条沿用 merge 的口径；若未来组织要求发布比合并更严
+（无链即不发布），那是立项时另议的语义变更，不在本轨
+偷偷改（见 §6 待拍板项）。
+
+### 2.5 只读性：检查绝不能写链
+
+- evaluator 不 append、不 commit、不调 `AuthStore.audit`、
+  不关调用方的连接。契约测试 `test_evaluator_is_read_only`
+  钉住：两次求值后链头不变、链仍 verify ok。
+- 为什么必须如此：`AuthStore.audit` 会同事务写一条链记录；
+  若检查写审计，检查本身就移动链头，检查前取的锚点立刻
+  失效，锚点校验将永远对不上——检查就不再是检查。
+  现有 `GET /admin/audit-ledger/verify` 成功路径同样不写审计，
+  正是同一道理。
+- 推论：409 阻塞不写审计（§2.2）；403 被拒沿用 `_audit_admin`
+  惯例写审计时，运维须知**链头已移动**，下一次锚点必须在
+  该行之后重取（锚点轮换见 §5.4）。
+
+### 2.6 `release_blocked` 与 `merge_blocked` 的关系
+
+- **合并放行 ≠ 发布放行**。`merge_blocked=false` 只说明
+  “合并那一刻链上无阻塞且五项全过”；发布时刻链可能已
+  新增推回、CI 可能已变红、合同可能已变——发布必须重新
+  读链、重新判定。拿合并时的 200 当发布通行证是本设计
+  明确禁止的用法，evaluator 的签名即防住了它：它不接受
+  “合并时的 gate 对象”作为输入，只接受调用方现算的
+  `hard_gate`，且 `hard_gate=None` 直接阻塞。
+- 反向亦然：发布阻塞不回滚合并状态。发布 409 时任务仍为
+  `merged`；修复后重调发布即可，不必重新合并。
+- `release_blocked` 与 `merge_blocked` 在 reader 里是同一
+  布尔值（`gate_block` 同时置两字段），但**求值时刻不同**：
+  同一个 reader、两次调用、两次时刻——这才是两字段并存的
+  意义，而不是“合并时顺带算好发布结论”。
+
+### 2.7 CORRECTED 为 pass 在发布端如何体现
+
+- 沿用 #247/#244 已裁决的语义，不发明新语义：审计的审计
+  把原结论纠正为 `pass`，**本身不解封**——它只表示“原判错了，
+  应安排重审”，不是一次重审。发布端与合并端共用同一 reader，
+  因此发布端自动继承该语义：纠正后、无新通过结论时，发布
+  仍 409（`release_blocked_audit_pushback`）。
+- 解封的唯一路径：一条**新的**通过结论进链——新的
+  `audit_verdict=pass`，或一次通过的 `re_reviewed` 推回轮次
+  （且 QA 失败链接须按 #247 的 QA 护栏全部重跑通过，否则
+  该通过结论写不进链）。
+- 契约测试 `test_corrected_to_pass_still_blocks_until_fresh_pass`
+  用**唯一阻塞**构造钉住这一点：若纠正本身能解封，该测试
+  必失败（测试注释说明了为何不用“纠正 + 另一失败”的掩盖构造）。
+
+## 3. evaluator 求值顺序（`cloud/release_gate.py`）
+
+1. 读链。异常 → `release_blocked_state_unavailable`，短路
+   （没有可信链读数时，其它结论都不可信）。
+2. 任务状态（仅当调用方给了 `task_status` 时）。非 `merged`
+   → `release_requires_merged`。
+3. 硬门禁。`hard_gate=None` → `release_hard_gate_evidence_missing`；
+   `allowed=false` → `release_blocked_hard_gate`，`blocks` 原样带出。
+4. 审计推回。reader 说阻塞 → `release_blocked_audit_pushback`，
+   `failed_checks` / `round` / `modules` 原样带出。
+5. 以上全过 → `allowed=true`，`http_status=200`，
+   `code=release_allowed`。
+
+多源同时阻塞时，`blocked_sources` 列出全部，`code` /
+`blocked_by` 只取求值顺序第一项。端点返回时不得丢弃
+`blocked_sources`。
+
+## 4. 契约测试（`cloud/tests/test_release_gate.py`，11 项）
+
+测试只测 evaluator + 本地 SQLite 链（`TemporaryDirectory`，
+跑完删除），**不部署、不调用生产发布流程**（生产本就没有
+发布端点可调）。覆盖：
+
+| 测试 | 断言 |
+|---|---|
+| 审计推回阻塞（硬门禁全过时） | 409 + `release_blocked_audit_pushback` + `failed_checks` 含 `ci_green` + `round=1` |
+| 重审通过后放行（新硬门禁全过） | 200 + `release_allowed` |
+| 纠正为 pass 但无新通过结论时仍阻塞；新通过结论后放行 | 前 409、后 200（唯一阻塞构造，见 §2.7） |
+| 链读失败（已关闭的连接） | 409 + `release_blocked_state_unavailable` |
+| 硬门禁失败而链已清 | 409 + `release_blocked_hard_gate` + `blocks` 非空，且不含审计阻塞码 |
+| 两源同时阻塞 | `blocked_sources` 同时含两码，`blocks` 与 `failed_checks` 均非空 |
+| 硬门禁证据缺失 | 409 + `release_hard_gate_evidence_missing` |
+| 任务未合并 | 409 + `release_requires_merged` |
+| 合并时放行、发布时链已阻塞 | 前 200、后 409（证明每次调用都重读链） |
+| 仅修复不解封 | fix 行后仍 409 |
+| evaluator 只读 | 两次求值后链头不变、链 verify ok |
+
+## 5. 账本锚点运维流程
+
+### 5.1 存放位置（推荐一支 + 取舍 + 权限）
+
+**推荐：独立对象存储（与生产库不同机、不同账号、不同权限）。**
+
+- 每个锚点一个对象，命名
+  `anchor-<YYYYMMDD-HHMMSS>-<count>-<head8>.json`，内容即
+  §5.2 的锚点文件（`{version, head_hash, count, anchored_at,
+  source}`，仅 `head_hash` + `count` 参与校验）。
+- 存储桶开启**版本控制 + 对象锁定/保留（WORM）或至少禁止
+  删除的桶策略**：写锚点的账号只有 `PutObject`，没有
+  `DeleteObject`、没有覆盖保留期的权限；读锚点的账号（审计
+  员）只有 `GetObject`。写与读、锚点与生产库，账号全部分开。
+- `current` 指针（如有）只是一个方便引用的独立小对象，
+  更新指针绝不删除旧锚点对象；历史锚点对象本身就是真相，
+  指针丢了可以从对象列表重建，对象丢了指针毫无意义。
+
+取舍（为什么不选其它位置）：
+
+| 候选位置 | 否决/降级原因 |
+|---|---|
+| 生产库同一张表/同库另一张表 | 与生产库同权限：能改链的人就能改锚点，锚点失去独立见证意义 |
+| 生产主机上的文件 | 与生产库同机：主机被拿下则锚点与链一起被改写；且主机文件无版本控制，易被覆盖 |
+| 运维人员个人机器文件 | 可作**过渡**（见下），但单点、无审计、无保留策略，人员变动即丢失 |
+| Git 仓库 | 历史可查是优点，但锚点文件进仓等于把“见证”交给与代码同一套合并权限，且 head 频繁更新会污染提交历史；不推荐为主存 |
+
+**过渡方案（在对象存储未就绪前，须用户拍板后才用）**：
+锚点文件存到一台**非生产主机**的运维账号目录（`0600`），
+该账号与生产库账号不同、无生产库写权限；同时把锚点
+`head_hash` 抄送到第二渠道（如运维群/邮件归档）作人工见证。
+过渡不是终态：对象存储就绪后，历史锚点文件应原样迁入
+对象存储并保留过渡期的抄送记录，不得“迁入时重算头哈希”。
+
+### 5.2 校验什么、多久一次、谁触发
+
+每次校验（脚本 `tools/ledger_anchor_check.py`）做两层：
+
+1. **链完整性**：`verify_chain` / `verify_export`——逐条重算
+   `entry_hash` + `prev_hash` 链接。中间篡改、重排、删中间
+   记录，在此层失败。
+2. **锚点前缀比对**：当前链条数 ≥ 锚点 `count`，且第 `count`
+   条的 `entry_hash` 仍等于锚点 `head_hash`。条数变少 →
+   锚定后的尾巴被截断；该位置哈希变了 → 锚点前的链被
+   替换/重写。头哈希**前进**（条数更多、前缀一致）是正常
+   通过，不是失败。
+
+周期（推荐值，待用户拍板，见 §6）：
+
+| 触发 | 动作 |
+|---|---|
+| 每日定时（cron/定时任务，运维账号） | 取最新锚点 → 全链校验 + 前缀比对；通过则取新锚点（轮换见 §5.4） |
+| 每次发布前（未来发布端点立项后） | 发布流程先跑一次锚点校验；校验失败即发布 409（与 §2.4 的链读失败同级处理，属未来端点行为，本轨不实现） |
+| 每次合并门禁异常/人工介入后 | 运维手动跑一次，确认链未被介入改动 |
+| 锚点轮换时 | 新锚点必须先通过旧锚点的前缀校验，才能成为“当前锚点”（见 §5.4） |
+
+校验脚本本身不触发任何业务动作：它只读（SQLite 用
+`mode=ro` 打开；导出模式只读文件），不写链、不发通知——
+通知由调用它的定时任务/运维流程负责（见 §5.3）。
+
+### 5.3 校验失败的告警与处理（绝不能静默重建）
+
+失败分两类，处理不同，但有一条共同红线：
+
+> **红线：绝不能删除旧链、重建整链、重算头哈希后冒充
+> “没发生”。** 任何恢复都必须保留原始链与旧锚点，恢复
+> 动作本身也要留痕（新锚点系列注明事件编号，见 §5.4）。
+
+- **告警给谁**：全局管理员 + 当值运维（渠道由用户定：
+  本轨不假设已有告警通道；定时任务失败时至少要在定时
+  任务日志与运维值班渠道留一条可查记录，不能只打印到
+  没人看的日志文件里）。
+- **是否冻结**：校验失败期间，**发布立即冻结**（不发布；
+  未来发布端点立项后以校验失败作 409 条件之一；立项前由
+  运维人工冻结发布操作）。合并是否冻结由当值全局管理员
+  当场决定并记录——本轨不以代码自动冻结合并（那会是
+  新的门禁语义，须另行立项），但 runbook 要求管理员在
+  收到告警后 1 个工作日内给出“冻结合并与否”的书面决定，
+  不能无决定地继续合并。
+- **恢复步骤**：
+  1. 立即对生产库做只读快照/备份，冻结现场（不要先修链）。
+  2. 区分失败类：锚点文件笔误/取错（旧锚点系列中存在能
+     通过前缀校验的锚点）→ 以那个锚点为准重取当前锚点，
+     并记录“锚点取错事件”；链本身失败（重算哈希不符、
+     链接断裂、前缀对不上任何历史锚点）→ 链不可信。
+  3. 链不可信时：旧链**原样封存**（只读，不删不改），
+     新链只能以“事件后新系列”起头（新 genesis 标记注明
+     事件编号与旧链封存位置），新锚点系列与旧系列分开存放、
+     不得混写；旧系列永不删除。
+  4. 恢复后重新锚定：新锚点只能取自**已通过内部校验且
+     通过最老可信锚点前缀校验**的链；若无任何可信锚点，
+     新系列首锚点必须注明“无可信前缀、事件后重建”，不得
+     写成与旧系列连续的样子。
+
+### 5.4 锚点轮换与历史锚点保留
+
+- **轮换**：每次校验通过后取新锚点（新文件、新对象），
+  旧锚点文件/对象**永不覆盖、永不删除**。新锚点生效前必须
+  通过旧锚点的前缀校验——通不过的链不配产生新锚点。
+- **保留期**：锚点文件极小（约 200 字节），**建议永久保留
+  全部历史锚点**，不设删除期；对象存储侧以版本控制 +
+  保留策略保证“删不掉”，而不是靠运维自觉不删。若存储
+  成本政策强制设限，则下限为：至少保留最近 12 个月的
+  每日锚点 + 每次发布前的锚点，且删除须全局管理员双人
+  确认并留审计记录——该下限须用户拍板（见 §6），本轨
+  不擅自把“永久”降级为某个期限。
+- **交接**：新旧锚点交接只认“新锚点通过旧锚点前缀校验”
+  这一条；指针（`current`）更新失败不影响历史锚点的有效性，
+  下次校验可直接用任意历史锚点重跑。
+
+### 5.5 校验脚本用法与退出码
+
+```
+# SQLite 本地链（只读打开，不写链）：
+python3 tools/ledger_anchor_check.py --db /path/to/control.db
+python3 tools/ledger_anchor_check.py --db /path/to/control.db --anchor /path/to/anchor.json
+
+# 生产 PG：先经 GET /admin/audit-ledger/export 导出，再验导出（脚本不开 PG 连接）：
+python3 tools/ledger_anchor_check.py --export /path/to/export.json --anchor /path/to/anchor.json
+# 校验通过后取新锚点（仅 --export 模式；失败时拒绝写文件，见 §5.5 末）：
+python3 tools/ledger_anchor_check.py --export /path/to/export.json --write-anchor /path/to/new-anchor.json
+# --db 模式取新锚点：用通过的那次检查输出的 head_hash/count，按 §5.2 格式写新锚点文件
+# （脚本不代写，避免“检查脚本写文件”与“只读检查”的语义混淆；--export 模式的 --write-anchor
+#  只写锚点文件、从不写链，失败时同样拒绝）。
+```
+
+退出码：`0` 通过；`1` 校验失败（stdout JSON 的 `failures`
+逐条列出失败项，`head_advanced_by` 为负即链比锚点短）；
+`2` 用法/IO 错误（文件不存在、锚点格式非法、`--db` 传了
+Postgres URL）。输出为单 JSON 对象，便于定时任务解析。
+
+脚本的三类本地实测（测试链在 `/tmp`，跑完删除，不进提交）：
+
+| 用例 | 结果 |
+|---|---|
+| 正常链（2 条）+ 锚点（同链头） | 退出 0，`head_advanced_by=0`；再追加 1 条后重验仍退出 0，`head_advanced_by=1`（头前进属正常） |
+| 特权篡改（删触发器后改第 1 条 detail；注：正常 SQL 的 UPDATE 本就被 SQLite 触发器挡下，实测先确认触发器拦截，再模拟特权篡改） | 退出 1，`failures=["entry_hash mismatch at id 1 (record tampered)"]` |
+| 删尾巴（删触发器后删最后 1 条）后与旧锚点比对 | 退出 1，`failures=["chain shorter than anchor: current count 1 < anchored count 2 ..."]` |
+| 附加：导出模式失败时 `--write-anchor` 被拒绝（无文件生成）；不存在的 DB 与 Postgres URL 均退出 2 | 均符合 |
+
+脚本退出码另有单元测试钉住（`cloud/tests/test_ledger_anchor_check.py`，
+子进程跑脚本，断言三类用例的退出码与关键失败文案）。
+
+### 5.6 真实 PG：本轨不做、只以常量/适配层证据写清
+
+- 本机无真实 PG，PG 触发器（`cloud/ledger.py` 的
+  `PG_GUARD_SQL` 常量）**未在真实 PG 上验证**，沿用 #241
+  的标注，不在本轨改口称已验证。
+- PG 路径的操作流程（生产 PG 须运维手动执行并验证后才认）：
+  1. 在生产 PG 上手动执行 `PG_GUARD_SQL`（函数 + 两触发器），
+     并实测 UPDATE/DELETE 被拒绝；
+  2. 经 `GET /admin/audit-ledger/verify`（全局管理员）确认
+     `ok=true`；
+  3. 经 `GET /admin/audit-ledger/export` 取导出，用本脚本
+     `--export` 模式 + 历史锚点校验；
+  4. 通过后按 §5.4 取新锚点存入对象存储。
+- 在 PG 验证完成前，生产 PG 的“已加固”状态一律写为
+  “未验证”，不得在 PR 正文或摘要里写成已验证。
+
+## 6. deploy.py 口径：为什么不在门禁内、未来是否纳入
+
+**判断：deploy.py 不纳入合并/发布门禁，且未来也不应纳入。**
+
+- **走什么路径**：`deploy/deploy.py` 是运维人员在本机跑的
+  CLI：打包/传包（tar 或主机 git 直拉）→ 主机
+  `host_deploy.sh` 换 release 目录 → 重启控制面 unit。
+  它部署的是**平台本身**（服务端代码），不是某个任务的
+  合并产物；它没有任务 id、没有调用方提交的门禁证据、
+  不走服务端 HTTP 鉴权（走 SSH deploy key），与
+  `POST /tasks/{id}/merge` / 未来 `POST /tasks/{id}/release`
+  根本不在同一层。
+- **为什么不在门禁内**：门禁的客体是“任务能否合并/发布”，
+  deploy.py 的客体是“平台代码能否上线”。把 deploy.py 绑到
+  任务链状态上，会在平台本身出问题、最需要部署修复与回滚
+  的时候反锁部署（回滚 `rollback.sh` 同样在门禁外，理由相同）。
+  紧急修复被门禁挡住，比“部署时没查任务链”危险得多。
+- **未来是否纳入**：不纳入为原则；只加两条不阻塞的运维
+  配合（均不改 deploy.py 行为、不设卡）：
+  1. 部署完成后，运维手动跑一次 §5.2 的锚点校验（部署不
+     应改链；若校验失败，按 §5.3 处理，与部署成功与否分开判）；
+  2. 部署说明里写明“部署 ≠ 任务发布”：推新平台版本不等于
+     发布任何任务，任务发布仍走未来发布端点。
+- 若未来有人提议“deploy.py 发布前查链”，须先回答：查哪
+  个任务的链？以谁的身份？回滚时查不查？答不上来就不纳入
+  ——本轨已把这三个问题写进 PR 正文，供立项时复核。
+
+## 7. 未做项与诚实边界（本轨明确不声称的）
+
+- 未建发布端点：无路由、无 HTTP 测试、无任务状态变更、
+  无真实发布动作；`release_gate.py` 只是 evaluator + 契约。
+- 未部署、未跑 `deploy.py`、未动生产、主机 env、系统 key、
+  sub2api、生产网关、仓库可见性、GitHub App 权限、生产容器。
+- 未在真实 PG 上验证：PG 触发器语法、PG 上的链校验与锚点
+  流程，均只以常量/导出模式写清，须生产 PG 手动执行并验证。
+- 未替用户拍板：发布端点是否立项、锚点对象存储选型与
+  账号、校验周期（推荐每日 + 每次发布前）、告警渠道、
+  锚点保留期下限、合并冻结与否的默认策略——见 §8。
+- 未改 v1.1 契约、分支保护决策、已有 PR 分支与主 checkout。
+
+## 8. 用户侧仍需拍板的点（本轨不擅自决定）
+
+1. 发布端点是否立项：立项则按 §2 实现 `POST /tasks/{id}/release`；
+   不立项则 `release_blocked` 继续只随合并响应返回，发布仍无
+   服务端强制——该风险须用户知晓。
+2. 锚点存放：对象存储选型（厂商/桶/账号）与过渡方案是否启用。
+3. 校验周期：推荐每日定时 + 每次发布前；是否接受该周期。
+4. 告警渠道：校验失败通知全局管理员与当值运维的具体渠道。
+5. 锚点保留期：推荐永久保留；若设下限，接受“12 个月每日 +
+   每次发布前锚点、双人确认删除”与否。
+6. 合并冻结默认策略：校验失败时合并是“管理员当场决定”还是
+   “默认冻结”（本轨推荐前者、代码不自动冻结）。
+7. 发布比合并更严的口径：无链（表不存在）时发布是否也应阻塞
+   （本轨沿用 merge 的“无链即无阻塞”，改严须立项时定）。
diff --git a/tools/ledger_anchor_check.py b/tools/ledger_anchor_check.py
new file mode 100644
index 0000000..75eb9c9
--- /dev/null
+++ b/tools/ledger_anchor_check.py
@@ -0,0 +1,264 @@
+#!/usr/bin/env python3
+"""Ledger anchor check: verify a hash chain against an external anchor.
+
+Read-only by construction, and that is the point:
+
+- ``--db`` opens SQLite with ``mode=ro`` (read-only URI). The
+  script never appends, never updates, never deletes, and never
+  calls ``AuthStore.audit`` -- writing a row would move the chain
+  head and make the check itself unreproducible (the same rule
+  the ``GET /admin/audit-ledger/verify`` endpoint follows on its
+  success path). A check that writes is not a check.
+- ``--export`` reads a JSON export (e.g. from
+  ``GET /admin/audit-ledger/export``) and verifies it in memory.
+  This is the path for production Postgres: this script does NOT
+  open a Postgres connection, and it never pretends to. PG
+  verification is: export via the admin endpoint, then run this
+  script in ``--export`` mode against the stored anchor.
+- ``--write-anchor`` (``--export`` mode only) writes an ANCHOR
+  FILE (outside the DB), never the chain, and only after the
+  internal chain verification has passed. Writing an anchor from
+  a failing chain would launder tampering into a fresh "trusted"
+  head, so the script refuses (no file written) when verification
+  fails. With ``--db``, take the anchor from the passing check's
+  reported head/count via the documented procedure instead.
+
+What is checked, in order (all failures are reported, exit 1):
+
+1. Internal integrity: linkage (each ``prev_hash`` equals the
+   previous ``entry_hash``) + recomputed ``entry_hash`` per row,
+   via ``cloud.ledger.verify_chain`` / ``verify_export``. This
+   catches middle tampering, reordering, and middle deletion.
+2. Anchor prefix (only when ``--anchor`` is given): the anchor
+   records ``{head_hash, count}`` taken at an earlier time. The
+   current chain must still contain that prefix: it must have
+   at least ``count`` entries, and the entry at position
+   ``count`` (1-based) must still hash to ``head_hash``. A
+   shorter chain means the anchored tail was truncated; a
+   different hash at that position means the chain was replaced
+   or rewritten before the anchor point. A head that has ADVANCED
+   past the anchor (more entries, same prefix) is NORMAL and
+   passes -- anchors are points in history, not a frozen head.
+   The honest limit, stated not hidden: an anchor cannot detect
+   deletion of entries added AFTER that anchor was taken (the
+   chain then still ends exactly at the anchor head). That is
+   why anchors must be taken frequently: the anchor cadence
+   bounds the undetectable window, and the next anchor catches
+   what this one could not.
+
+Anchor file format (JSON)::
+
+    {"version": 1, "head_hash": "<64 hex>", "count": <int>,
+     "anchored_at": "<ISO timestamp, informational only>",
+     "source": "<db path / export description, informational>"}
+
+``anchored_at`` and ``source`` are never trusted by the check:
+only ``head_hash`` + ``count`` decide pass/fail.
+
+Exit codes: 0 = pass, 1 = verification failure (failures listed
+in the JSON output), 2 = usage / I/O error (missing file, bad
+anchor format, Postgres URL passed as ``--db``). Output is one
+JSON object on stdout, so a cron job or operator can parse it
+without scraping prose.
+"""
+
+import argparse
+import json
+import os
+import re
+import sqlite3
+import sys
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(
+    os.path.abspath(__file__))))
+
+from cloud.ledger import verify_chain, verify_export  # noqa: E402
+
+_HEX64 = re.compile(r"^[0-9a-f]{64}$")
+
+
+def _load_anchor(path):
+    try:
+        with open(path, "r", encoding="utf-8") as handle:
+            data = json.load(handle)
+    except (OSError, ValueError) as exc:
+        raise ValueError("cannot read anchor %r: %s" % (path, exc))
+    if not isinstance(data, dict):
+        raise ValueError("anchor %r is not a JSON object" % path)
+    head = data.get("head_hash")
+    count = data.get("count")
+    if not isinstance(head, str) or not _HEX64.match(head):
+        raise ValueError(
+            "anchor %r: head_hash must be a 64-char lowercase hex"
+            " sha256" % path)
+    if isinstance(count, bool) or not isinstance(count, int) \
+            or count < 0:
+        raise ValueError(
+            "anchor %r: count must be a non-negative int" % path)
+    if count == 0:
+        raise ValueError(
+            "anchor %r: count 0 anchors nothing (empty chain); "
+            "take an anchor only after at least one entry exists"
+            % path)
+    return {"head_hash": head, "count": count}
+
+
+def _check_prefix(entry_hashes, anchor):
+    """Anchor-prefix check. Returns a list of failures (empty = pass)."""
+    count = anchor["count"]
+    if len(entry_hashes) < count:
+        return [
+            "chain shorter than anchor: current count %d < anchored"
+            " count %d (anchored tail truncated or chain replaced)"
+            % (len(entry_hashes), count)]
+    if entry_hashes[count - 1] != anchor["head_hash"]:
+        return [
+            "anchor prefix mismatch: entry %d hashes to %s, not the"
+            " anchored head %s (chain replaced or rewritten before"
+            " the anchor point)"
+            % (count, entry_hashes[count - 1], anchor["head_hash"])]
+    return []
+
+
+def _report(ok, failures, count, head_hash, anchor):
+    report = {
+        "ok": ok,
+        "failures": failures,
+        "count": count,
+        "head_hash": head_hash,
+        "anchor": anchor,
+        "head_advanced_by": (
+            count - anchor["count"] if anchor is not None else None),
+    }
+    print(json.dumps(report, indent=2, sort_keys=True))
+    return 0 if ok else 1
+
+
+def _run_db(db_path, anchor):
+    if "://" in db_path or db_path.startswith("postgres"):
+        raise ValueError(
+            "--db takes a SQLite file path, not a Postgres URL. "
+            "For Postgres, export via GET /admin/audit-ledger/export"
+            " and run this script with --export.")
+    if not os.path.exists(db_path):
+        raise ValueError("db file not found: %r" % db_path)
+    uri = "file:%s?mode=ro" % _quote(db_path)
+    conn = sqlite3.connect(uri, uri=True)
+    try:
+        result = verify_chain(conn)
+        rows = conn.execute(
+            "SELECT entry_hash FROM audit_ledger ORDER BY id ASC"
+        ).fetchall() if result["count"] else []
+    finally:
+        conn.close()
+    failures = list(result.get("failures") or [])
+    entry_hashes = [row[0] for row in rows]
+    if anchor is not None:
+        failures.extend(_check_prefix(entry_hashes, anchor))
+    return _report(not failures, failures, result["count"],
+                   result["head_hash"], anchor)
+
+
+def _quote(path):
+    # Minimal URI escaping for the read-only open: '#' and '?'
+    # would otherwise terminate the URI. A path containing them
+    # is unusual; escaping keeps the open honest instead of
+    # silently opening a different file.
+    return path.replace("?", "%3F").replace("#", "%23")
+
+
+def _run_export(export_path, anchor):
+    try:
+        with open(export_path, "r", encoding="utf-8") as handle:
+            data = json.load(handle)
+    except (OSError, ValueError) as exc:
+        raise ValueError(
+            "cannot read export %r: %s" % (export_path, exc))
+    result = verify_export(data)
+    entries = data.get("entries") if isinstance(data, dict) else None
+    entry_hashes = []
+    if isinstance(entries, list):
+        entry_hashes = [e.get("entry_hash") for e in entries
+                        if isinstance(e, dict)]
+    failures = list(result.get("failures") or [])
+    failures.extend(_check_prefix(entry_hashes, anchor)
+                    if anchor is not None else [])
+    return _report(not failures, failures, result["count"],
+                   result["head_hash"], anchor)
+
+
+def _write_anchor(out_path, head_hash, count, source):
+    import datetime
+    payload = {
+        "version": 1,
+        "head_hash": head_hash,
+        "count": count,
+        "anchored_at": datetime.datetime.now(
+            datetime.timezone.utc).isoformat(),
+        "source": source,
+    }
+    tmp_path = out_path + ".tmp"
+    with open(tmp_path, "w", encoding="utf-8") as handle:
+        json.dump(payload, handle, indent=2, sort_keys=True)
+        handle.write("\n")
+    os.replace(tmp_path, out_path)
+    print(json.dumps({"anchor_written": out_path, **payload},
+                     indent=2, sort_keys=True))
+
+
+def main(argv=None):
+    parser = argparse.ArgumentParser(
+        description="Verify an audit hash chain against an external"
+                    " anchor (read-only; exit 0 pass, 1 fail, 2 usage).")
+    group = parser.add_mutually_exclusive_group(required=True)
+    group.add_argument("--db", help="SQLite control.db file path")
+    group.add_argument("--export",
+                       help="JSON file from /admin/audit-ledger/export")
+    parser.add_argument("--anchor",
+                        help="anchor JSON file ({head_hash, count})")
+    parser.add_argument("--write-anchor",
+                        help="after a passing check, write a fresh"
+                             " anchor JSON to this path (anchor file"
+                             " only, never the chain; refused on failure)")
+    args = parser.parse_args(argv)
+    try:
+        anchor = _load_anchor(args.anchor) if args.anchor else None
+    except ValueError as exc:
+        print("error: %s" % exc, file=sys.stderr)
+        return 2
+    if args.db and args.write_anchor:
+        # Refused before any check runs, so a passing report is
+        # never followed by a contradictory exit code. Anchor
+        # taking from a DB check uses the documented procedure:
+        # run the check, then write the reported head/count as a
+        # new anchor file (the file, never the chain).
+        print("error: --write-anchor is not combined with --db;"
+              " take the anchor from the passing check's"
+              " head_hash/count via the documented procedure",
+              file=sys.stderr)
+        return 2
+    try:
+        if args.db:
+            return _run_db(args.db, anchor)
+        code = _run_export(args.export, anchor)
+        if code == 0 and args.write_anchor:
+            # Re-read the export to obtain the verified head.
+            with open(args.export, "r", encoding="utf-8") as handle:
+                data = json.load(handle)
+            _write_anchor(args.write_anchor, data["head_hash"],
+                          len(data["entries"]), args.export)
+        elif args.write_anchor:
+            print("error: refusing --write-anchor: verification"
+                  " failed, an anchor from a failing chain would"
+                  " launder tampering", file=sys.stderr)
+        return code
+    except ValueError as exc:
+        print("error: %s" % exc, file=sys.stderr)
+        return 2
+    except sqlite3.Error as exc:
+        print("error: sqlite: %s" % exc, file=sys.stderr)
+        return 2
+
+
+if __name__ == "__main__":
+    sys.exit(main())