WARDEN-WP-0031 T04: prove ops-warden's caller identity against the live pin

flex-auth's binding names system:serviceaccount:ops-warden:ops-warden, and that
ServiceAccount did not exist. deploy/kubernetes/caller-identity.yaml creates it
plus its namespace — no RBAC, automount off; it is never used to call the
Kubernetes API, only to be TokenReviewed. Applied to the railiance01 cluster.

Operator warden.yaml now uses caller_auth mode: command (kubectl create token,
audience flex-auth, 10m). Gate exits 0 live against a port-forward of the pin:
HTTP 200, effect=allow, decision:f3f7c88f9585582a.

The evidence is not that allow — warn allows anonymous callers too. It is that
the pin's "caller authentication warning" count held at 4 across two
authenticated runs. That is the ADHOC-2026-08-17-T01 condition.

Also gives the readiness probe a structurally complete context, so a deny means
the policy said no rather than the probe being malformed.

policy.enabled stays false. T05 waits on flex-auth setting callerAuth.mode:
enforce (their FLEX-WP-0016 T03).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

scripts/check_policy_caller_identity.py

@@ -97,7 +97,11 @@ def run_checks(config_path: Optional[Path], url: Optional[str]) -> List[Check]:
     import httpx  # local import: the offline checks above must not need it
 
     probe = {
-        "subject": {"id": "readiness", "type": "agt", "tenant": policy.tenant},
+        "subject": {
+            "id": "agt-state-hub-bridge",
+            "type": "agt",
+            "tenant": policy.tenant,
+        },
         "action": "sign",
         "resource": {
             "id": "ssh-cert:actor/agt-state-hub-bridge",
@@ -105,7 +109,17 @@ def run_checks(config_path: Optional[Path], url: Optional[str]) -> List[Check]:
             "system": policy.system,
             "tenant": policy.tenant,
         },
-        "context": {"readiness_probe": True},
+        "context": {
+            # A structurally complete context, so a deny means the policy said
+            # no — not that the probe was malformed. What is under test here is
+            # the caller identity, and that is answered by the HTTP status.
+            "actor_name": "agt-state-hub-bridge",
+            "actor_type": "agt",
+            "principals": ["agt-task-bridge"],
+            "ttl_hours": 24,
+            "pubkey_fingerprint": "sha256:" + "0" * 64,
+            "readiness_probe": True,
+        },
     }
     try:
         response = httpx.post(