fix(bridge): use /state/health for readiness probe

The actcore-state-hub-bridge readiness probe hit /state/summary through
the tunnel proxy chain. Cold-cache summary requests and intermittent
tunnel stalls routinely exceeded the 5s probe timeout (1584 failures
over 17h), leaving the pod 0/1 Ready and breaking hourly/triage sinks.

Use /state/health instead — same signal the ops inventory already
expects, and completes in ~30ms through the bridge.

k8s/railiance/20-runtime.yaml

@@ -630,7 +630,7 @@ spec:
               ThreadingHTTPServer(("0.0.0.0", 18080), Proxy).serve_forever()
           readinessProbe:
             httpGet:
-              path: /state/summary
+              path: /state/health
               port: http
             initialDelaySeconds: 5
             periodSeconds: 10