feat: implement real-time booking updates using Server-Sent Events (SSE) and add public booking URL sharing to the dashboard

AGENTS.md

@@ -53,6 +53,19 @@ The project uses **Better Auth** for session management, replacing the legacy Su
 - **Zod v4**: Use `.issues` instead of `.errors` for validation errors.
 - **TanStack Router**: Routes are code-generated. Use `--filter frontend build` not raw vite build.
 
+## Real-time Updates (SSE)
+
+The project uses **Server-Sent Events (SSE)** for real-time booking updates in the admin panel.
+
+- **Backend**: `apps/backend/src/lib/sse.ts` provides the `sseManager` and SSE endpoint `/api/events/:channel`.
+- **Event flow**: When a public booking is created, the handler emits to channel `complex:{complexId}`.
+- **Frontend**: `home-page.tsx` connects to the SSE endpoint and invalidates the bookings query on new events.
+
+**Important - Multi-process limitation**: The current SSE implementation works with a single Bun process only. If you deploy with multiple workers (e.g., clustering in Dokploy), events won't be shared across workers. For production with multiple workers, use Redis for pub/sub:
+- Install `@hono/node-server` or a Redis client
+- Replace `sseManager` with Redis pub/sub
+- Or fall back to Socket.io with Redis adapter
+
 ## Docker Deployment (Dokploy)
 
 - **Build Context**: `./` (monorepo root)