Add the WebSocket upgrade endpoint at /api/v1/ws with CORS origin
verification using the configured allowed origins. Includes nil hub
guard returning 503 if the WebSocket system hasn't been initialized.
Register the hub initialization in the app startup sequence and wire
the upgrade handler into the Echo router.
Add the core WebSocket infrastructure:
- Message type definitions for the wire protocol (subscribe, unsubscribe,
auth, error, push events)
- In-memory connection hub that tracks per-user connections and routes
messages to subscribed clients
- Connection wrapper with auth-after-connect flow: connections start
unauthenticated, client sends JWT as first message, only then can
subscribe to event topics
Includes auth timeout (30s), shared cancellation context for read/write
loops, hub map cleanup on last connection removal, and proper error
delivery before closing on auth failure.
kolaente