Implement SECRETS-WP-0008 unblocked layer-model obligations

Load pep-stance.yaml as the live unreachable-engine gate and record named
stance fields on privileged evidence. Classify evidence, queue load-bearing
records in a local outbox, and add heartbeat/drain commands that never sit
on a mutation path. Publish proposed SSH-CA and secret-use evidence
contracts without adding an OpenBao SSH-CA write.

T02 (access-engine decision records) and T06 (no standing credential) stay
wait on external endpoints.

Assistant: grok
Assistant-Session: 01a04cea-cb33-7c63-bad7-c1b0f9f0076b

layer.yaml

@@ -68,10 +68,13 @@ proposed_capabilities:
       (ops-warden) does not hold a direct VaultCA write.
     intended_owner: secrets-engine
     owner_status: proposed
+    contract: docs/ssh-ca-signing-contract.md
     blocked_on: >-
-      No engine API exists yet. ops-warden continues to sign through its
-      declared §5.3 gap. This repository accepts the engine surface and
-      declines operational ownership of the SSH access lane.
+      Contract published; ops-warden has not assented. No OpenBao SSH-CA
+      write is added to this CLI until that assent. ops-warden continues
+      to sign through its declared §5.3 gap. This repository accepts the
+      engine surface and declines operational ownership of the SSH access
+      lane.
     review: "2026-11-28"
     consequence: >-
       ops-warden's ssh-ca-signing-write gap remains the production path.
@@ -83,9 +86,11 @@ proposed_capabilities:
       exposed as an engine surface for kings-guard secret-abuse posture.
     intended_owner: secrets-engine
     owner_status: proposed
+    contract: docs/secret-use-evidence-contract.md
     blocked_on: >-
-      Local JSONL plus best-effort State Hub notes exist; they are not an
-      engine API and they are not audit-core. Completeness is not claimed.
+      Contract published; kings-guard has not assented. Local JSONL, the
+      load-bearing outbox, and `route`/`audit` are not this observation
+      API. Completeness is not claimed.
     review: "2026-11-28"
     consequence: >-
       kings-guard secret-abuse posture stays fixture-driven.
@@ -130,15 +135,29 @@ non_tooling_clients:
       preflight only and is deliberately not a write into OpenBao. Wiring it
       as OpenBao JWT login remains blocked on the platform-owned role.
 
+  - id: audit-core-outbox-drain
+    target: audit-core
+    layer: engine
+    modules:
+      - src/secrets_engine/evidence.py
+    operation: "Optional POST /v1/events from secrets-engine evidence drain"
+    write: true
+    note: >-
+      Engine-to-engine emit. Never on the mutation path. Empty URL skips
+      delivery and leaves the local outbox in place. Sender binding in
+      audit-core is not yet admitted.
+
 # §9.6 — what this repository may claim about evidence it writes today.
 evidence_bound:
-  kind: attributive
+  classification: evidence-classification.yaml
   proves:
     - local JSONL records that were written were not rewritten by this engine
+    - load-bearing records queued in evidence_dir/outbox/ were written
   does_not_prove:
     - that a record was ever sent to audit-core
     - absence of a record as evidence of non-occurrence
     - completeness of the trail
-  destination_today: "local JSONL plus best-effort State Hub progress notes"
+  destination_today: "local JSONL; load-bearing also queued locally; attributive State Hub notes"
   intended_destination: audit-core
   completeness_claimed: false
+  no_control_branches_on_presence: true