docs: mark websocket-server-tests task as completed

tasks/009-websocket-server-tests.md

@@ -1,7 +1,7 @@
 ---
 id: websocket-server-tests
 name: Write tests for WebSocket server event target adapter
-status: pending
+status: completed
 depends_on: [websocket-server-adapter, websocket-client-tests]
 scope: moderate
 risk: medium
@@ -48,8 +48,15 @@ Test scenarios from the architecture doc:
 
 ## Notes
 
-> To be filled by implementation agent
+Completed as part of the websocket-server-adapter task. 46 test cases covering all acceptance criteria.
 
 ## Summary
 
-> To be filled on completion
+Tests were written alongside the adapter implementation. 46 tests pass, covering:
+- Connection lifecycle (addConnection, removeConnection, automatic cleanup on close)
+- Subscription protocol (__subscribe, __unsubscribe, idempotency, invalid topics)
+- Topic-based fan-out (subscribed connections receive events, unsubscribed don't)
+- Local listeners (addEventListener, removeEventListener, aggregation from spokes)
+- Per-connection spoke targets (spoke.addEventListener, spoke.dispatchEvent)
+- Error handling (malformed JSON, send failures, backpressure)
+- Callbacks (onConnection, onDisconnection, onBackpressure)