fix(runner): use unbounded SSE tap queue

The bounded queue (maxsize=100) dropped events when no SSE consumer was
connected (e.g. CLI sessions, background agent runs). Each session queue
is ephemeral and drained or GC'd at run end, so unbounded buffering is
safe — worst case is transient memory growth during a long turn with no
consumer, which is acceptable given pod memory limits (4Gi).

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Ambient Code Bot

components/runners/ambient-runner/ambient_runner/app.py

@@ -150,7 +150,7 @@ async def lifespan(app: FastAPI):
             # This closes the race between listener.ready and the first event fan-out.
             active_streams = getattr(bridge, "_active_streams", None)
             if active_streams is not None and session_id not in active_streams:
-                active_streams[session_id] = asyncio.Queue(maxsize=100)
+                active_streams[session_id] = asyncio.Queue()
                 logger.info("Pre-registered SSE queue for session=%s", session_id)
 
         # Auto-execute prompts when present (skipped only for resumes,

components/runners/ambient-runner/ambient_runner/endpoints/events.py

@@ -69,7 +69,7 @@ async def get_events(thread_id: str, request: Request):
         )
         queue: asyncio.Queue = existing
     else:
-        queue = asyncio.Queue(maxsize=100)
+        queue = asyncio.Queue()
         active_streams[thread_id] = queue
         logger.info(
             "[SSE TAP] Queue registered: thread=%s (active_streams count=%d)",