Reduce log noise: downgrade periodic WebSocket rotation from ERROR to INFO

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/services/ws_client.py

@@ -93,6 +93,9 @@ async def connect_and_serve():
     while True:
         try:
             await _run_connection()
+        except ConnectionError:
+            logger.info("Connection rotated by server, reconnecting...")
+            await asyncio.sleep(5)
         except Exception:
             logger.exception("Connection lost, reconnecting in 5s...")
             await asyncio.sleep(5)