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.

tests/test_report_sinks.py

@@ -9,8 +9,9 @@ from activity_core.report_sinks import persist_reports
 
 
 class DummyResponse:
-    def __init__(self, payload: Any) -> None:
+    def __init__(self, payload: Any, *, status_code: int = 200) -> None:
         self.payload = payload
+        self.status_code = status_code
 
     def raise_for_status(self) -> None:
         return None