fix(feishu): queue inbound events when adapter loop not ready (#5499) (#11372)

Inbound Feishu messages arriving during brief windows when the adapter
loop is unavailable (startup/restart transitions, network-flap reconnect)
were silently dropped with a WARNING log. This matches the symptom in
issue #5499 — and users have reported seeing only a subset of their
messages reach the agent.

Fix: queue pending events in a thread-safe list and spawn a single
drainer thread that replays them once the loop becomes ready. Covers
these scenarios:

  * Queue events instead of dropping when loop is None/closed
  * Single drainer handles the full queue (not thread-per-event)
  * Thread-safe with threading.Lock on the queue and schedule flag
  * Handles mid-drain bursts (new events arrive while drainer is working)
  * Handles RuntimeError if loop closes between check and submit
  * Depth cap (1000) prevents unbounded growth during extended outages
  * Drops queue cleanly on disconnect rather than holding forever
  * Safety timeout (120s) prevents infinite retention on broken adapters

Based on the approach proposed in #4789 by milkoor, rewritten for
thread-safety and correctness.

Test plan:
  * 5 new unit tests (TestPendingInboundQueue) — all passing
  * E2E test with real asyncio loop + fake WS thread: 10-event burst
    before loop ready → all 10 delivered in order
  * E2E concurrent burst test: 20 events queued, 20 more arrive during
    drainer dispatch → all 40 delivered, no loss, no duplicates
  * All 111 existing feishu tests pass

Related: #5499, #4789

Co-authored-by: milkoor <milkoor@users.noreply.github.com>

scripts/release.py

@@ -53,6 +53,7 @@ AUTHOR_MAP = {
     "126368201+vilkasdev@users.noreply.github.com": "vilkasdev",
     "137614867+cutepawss@users.noreply.github.com": "cutepawss",
     "96793918+memosr@users.noreply.github.com": "memosr",
+    "milkoor@users.noreply.github.com": "milkoor",
     "131039422+SHL0MS@users.noreply.github.com": "SHL0MS",
     "77628552+raulvidis@users.noreply.github.com": "raulvidis",
     "145567217+Aum08Desai@users.noreply.github.com": "Aum08Desai",