feat(railiance): adopt state-hub edge relay beachhead for WP-0015

Deploy actcore-statehub-edge-relay, point STATE_HUB_URL at it, retire the
bespoke state-hub bridge, and accept edge-relay queued write receipts in
report and ops evidence sinks.

k8s/railiance/README.md

@@ -43,8 +43,11 @@ and a persistent working-memory volume mounted at
 Before trusting the daily 07:20
 Europe/Berlin schedule, verify both runtime dependencies:
 
-- `actcore-state-hub-bridge` can reach the State Hub API through the node-local
-  tunnel expected at `127.0.0.1:18000`.
+- `actcore-statehub-edge-relay` is ready and reports upstream reachability at
+  `GET /edge/health` (upstream is the in-cluster State Hub API at
+  `state-hub.state-hub.svc.cluster.local:8000`). `STATE_HUB_URL` points at the
+  relay so allowlisted `GET` reads can be served from cache during brief upstream
+  outages and queueable writes survive until replay.
 - `LLM_CONNECT_URL` points at the verified in-namespace llm-connect Service,
   `http://llm-connect.activity-core.svc.cluster.local:8080`, and the
   operator-owned provider Secret lets that Service serve the