feat(agent-office): 노드 헬스 1분 cron + 텔레그램 경보(다운/복구/dead-letter)

agent-office/tests/test_node_monitor.py

@@ -96,3 +96,31 @@ async def test_llen_exception_returns_redis_ok_false():
     )
     st = await node_monitor.collect_status(redis=r)
     assert st["redis_ok"] is False
+
+
+import app.node_monitor as nm
+
+@pytest.mark.asyncio
+async def test_alert_on_alive_to_dead(monkeypatch):
+    sent = []
+    async def fake_send_raw(text, **kw): sent.append(text); return {"ok": True}
+    monkeypatch.setattr("app.telegram.messaging.send_raw", fake_send_raw)
+    monkeypatch.setattr("app.db.add_log", lambda *a, **k: None)
+    nm._node_state.clear(); nm._dl_notified.clear()
+    alive = {"workers": [{"name":"image-render","alive":True,"dead_letter":0}], "links": []}
+    dead =  {"workers": [{"name":"image-render","alive":False,"dead_letter":0}], "links": []}
+    await nm.check_and_alert(status=alive)   # 첫 관측 — 경보 없음
+    assert sent == []
+    await nm.check_and_alert(status=dead)    # alive→dead 전이
+    assert any("다운" in t for t in sent)
+
+@pytest.mark.asyncio
+async def test_alert_on_dead_letter_growth(monkeypatch):
+    sent = []
+    async def fake_send_raw(text, **kw): sent.append(text); return {"ok": True}
+    monkeypatch.setattr("app.telegram.messaging.send_raw", fake_send_raw)
+    monkeypatch.setattr("app.db.add_log", lambda *a, **k: None)
+    nm._node_state.clear(); nm._dl_notified.clear()
+    s = {"workers": [{"name":"video-render","alive":True,"dead_letter":2}], "links": []}
+    await nm.check_and_alert(status=s)
+    assert any("dead-letter" in t for t in sent)