test: refresh regenerated destroy fixture and pin the vocabulary gap

flex-auth regenerated decision_destroy_dual_control so context.approval
carries a complete approval-claim including the now-required
binding.pdp_digest. Because context is part of the digest material, that
changed both the request digest and the context input-claim digest; the
vendored copy and its pins are updated. Our digest join reproduces the new
envelope digest exactly, so the digest_material fix holds.

Two properties are now asserted rather than described:

- The embedded claim's binding speaks approval-engine's vocabulary
  (secrets.kv.destroy, target {id, stage}) while the decision speaks ours
  (destroy, lane:...). That is the unpublished mapping, now a test.
- The claim's pdp_digest cannot equal the request digest of the request that
  carries it: embedding the claim in a hashed context changes that digest.
  It matches neither the full request nor the request with the claim
  removed. Raised with both teams; recorded here so a future change to it is
  visible rather than silent.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01M65ovP3eiiPHubibvWs9mD

Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 393550@bnt-lap001
Assistant-Session: 4bb359f9-1f12-4410-9e76-079cf23c82e4

tests/test_decision_replay.py

@@ -37,9 +37,9 @@ CASES = {
     },
     "destroy": {
         "file": "decision_destroy_dual_control.json",
-        "digest": "sha256:570d112890586d3cbf00c0e81c85ae7806f40f00afa1a2c0a23fd5e077a27f56",
+        "digest": "sha256:fc155dba88f8ab18b3032ed086ba2f455158c6981106e7829d520ab7b036bdf3",
         "action": "destroy",
-        "context_claim_digest": "sha256:45fa9f41271c684f2c26570be11869a8eda28e7b3b25f11e01f9378b6f89fdc8",
+        "context_claim_digest": "sha256:b0d2203cd2b43a9ba573c21c038154c131afba4255e313affd7ecf810e2cc221",
     },
 }
 
@@ -157,3 +157,46 @@ def test_expired_real_envelope_fails_closed():
             accepted_policy_packages={"secrets-engine.catalog-lane.lifecycle"},
             accepted_policy_versions={"v1"},
         )
+
+
+def test_embedded_claim_uses_approval_engine_vocabulary_not_ours():
+    """The published vocabulary gap, asserted rather than described.
+
+    The dual-control request carries a complete approval-claim in
+    context.approval. Its binding speaks approval-engine's language while the
+    decision speaks ours, and no mapping between them is published -- which is
+    why this engine compares pdp_digest and refuses to derive a native digest
+    from its own vocabulary.
+    """
+    envelope = _envelope("destroy")
+    claim = envelope["binding"]["context"]["approval"]
+    assert claim["kind"] == "approval-claim"
+    assert claim["issuer"] == "approval-engine"
+    assert claim["valid_now"] is True
+    assert claim["binding"]["action"] == "secrets.kv.destroy"
+    assert envelope["binding"]["action"] == "destroy"
+    assert claim["binding"]["action"] != envelope["binding"]["action"]
+    assert set(claim["binding"]["target"]) == {"id", "stage"}
+    assert claim["binding"]["target"]["id"] != envelope["resource"]["id"]
+
+
+def test_embedded_claim_pdp_digest_cannot_equal_the_carrying_request_digest():
+    """Carrying the claim inside a hashed context makes the two unequal.
+
+    context is part of the digest material, so embedding an approval-claim
+    changes the request digest of the very request that carries it. A
+    pdp_digest recorded at issue time therefore cannot equal the final digest
+    of the dual-control request. Raised with approval-engine and flex-auth; this
+    test records the property so a future change is visible rather than silent.
+    """
+    envelope = _envelope("destroy")
+    binding = envelope["binding"]
+    pdp = binding["context"]["approval"]["binding"]["pdp_digest"]
+    request = _request_from(envelope)
+    assert request_digest(request) == binding["request_digest"]
+    assert pdp != binding["request_digest"]
+    without_claim = dict(request)
+    without_claim["context"] = {
+        k: v for k, v in binding["context"].items() if k != "approval"
+    }
+    assert pdp != request_digest(without_claim)