Merge branch 'dev' into agent/rex/CUB-125-realtime-sse

- Add missing 'offline' to AgentStatus union type (types/index.ts)
- Add max-retry circuit breaker to useSSE; error state is now reachable
- Wire typed SSE payloads (SSEPayloadMap discriminated union) into useRealtimeSync
- Add Vitest + 20 unit tests: useSSE lifecycle, back-off, circuit breaker,
  event parsing, cleanup; useRealtimeSync event-to-invalidation mapping
- Rebase on dev to remove stale CUB-119 legacy-deletion commit and align
  CI workflow (dev already consolidated into single dev.yml)
- Tests: npm test → 20/20 pass; Build: npm run build → 0 errors

.env.example

@@ -32,7 +32,7 @@ GATEWAY_POLL_INTERVAL=5s
 # When using docker-compose, these are set in the services section
 # See docker-compose.yml for service-specific environment variables
 
-# ── Database Configuration ───────────────────────────────────────────────
+# ── Database Configuration ─────────────────────────────────────────────
 # Set in the db service environment section of docker-compose.yml
 # POSTGRES_USER=controlcenter
 # POSTGRES_PASSWORD=controlcenter

go-backend/cmd/server/main.go

@@ -112,7 +112,7 @@ func main() {
 	<-quit
 	slog.Info("shutting down server...")
 
-	cancel() // stop gateway clients
+	cancel() // stop gateway polling
 
 	shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), 15*time.Second)
 	defer shutdownCancel()

go-backend/internal/gateway/client.go

@@ -1,10 +1,6 @@
 // Package gateway provides an OpenClaw gateway integration client that
 // polls agent states, persists them via the repository layer, and broadcasts
 // changes through the SSE broker for real-time frontend updates.
-//
-// When a WSClient is wired via SetWSClient, the REST poller becomes a
-// fallback: it waits for the WS client to signal readiness, and only starts
-// polling if WS fails to connect within 30 seconds.
 package gateway
 
 import (
@@ -144,6 +140,7 @@ func (c *Client) poll(ctx context.Context) {
 	}
 
 	for _, ga := range agents {
+		// Check if agent already exists; if so, update; otherwise create.
 		existing, err := c.agents.Get(ctx, ga.ID)
 		if err != nil {
 			// Not found — create it