fix(k1): stabilize live recovery and media admission

tests/test_web_validation_security.py

@@ -40,6 +40,24 @@ class _FailingSendWebSocket:
         del code, reason
 
 
+class _DisconnectAfterSecondSendWebSocket:
+    def __init__(self) -> None:
+        self.accepted = False
+        self.send_count = 0
+
+    async def accept(self) -> None:
+        self.accepted = True
+
+    async def send_json(self, payload: dict[str, Any]) -> None:
+        del payload
+        self.send_count += 1
+        if self.send_count == 2:
+            raise WebSocketDisconnect(code=1001)
+
+    async def close(self, *, code: int, reason: str) -> None:
+        del code, reason
+
+
 async def _post_json(path: str, payload: dict[str, Any]) -> tuple[int, str]:
     body = json.dumps(payload).encode()
     request_sent = False
@@ -198,6 +216,25 @@ def test_device_plugin_events_treats_proven_transport_disconnect_as_completion(
     assert websocket.accepted is True
 
 
+def test_device_plugin_events_keeps_heavy_state_poll_off_live_media_cadence(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    websocket = _DisconnectAfterSecondSendWebSocket()
+    sleeps: list[float] = []
+
+    async def record_sleep(delay: float) -> None:
+        sleeps.append(delay)
+
+    monkeypatch.setattr(app_module, "plugin_dispatcher", _StateDispatcher())
+    monkeypatch.setattr(app_module.asyncio, "sleep", record_sleep)
+
+    asyncio.run(app_module.device_plugin_events(websocket, "test.plugin"))
+
+    assert websocket.accepted is True
+    assert sleeps == [app_module.DEVICE_PLUGIN_EVENT_POLL_INTERVAL_SECONDS]
+    assert sleeps[0] == 2.0
+
+
 def test_device_plugin_events_propagates_arbitrary_send_runtime_error(
     monkeypatch: pytest.MonkeyPatch,
 ) -> None: