fix: suppress WebSocket keepalive timeout tracebacks from stderr

app.py

@@ -27,6 +27,19 @@ os.makedirs(BASE_DIR / "logs", exist_ok=True)
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):
+    import asyncio
+    import warnings
+    from websockets.exceptions import ConnectionClosedError
+
+    def _handle_async_exception(loop, ctx):
+        exc = ctx.get("exception")
+        if isinstance(exc, ConnectionClosedError):
+            return
+        loop.default_exception_handler(ctx)
+
+    asyncio.get_event_loop().set_exception_handler(_handle_async_exception)
+    warnings.filterwarnings("ignore", message=".*ping timeout.*")
+
     logger.info("=" * 50)
     logger.info("  TurboSu - Racing Telemetry Dashboard")
     logger.info("=" * 50)