improve exception handling

app/main.py

@@ -3,6 +3,7 @@ from fastapi.staticfiles import StaticFiles
 from fastapi.responses import HTMLResponse
 from app.asr_worker import create_recognizer, stream_audio, finalize_stream
 import json
+from starlette.websockets import WebSocketDisconnect
 
 app = FastAPI()
 
@@ -37,7 +38,10 @@ async def websocket_endpoint(websocket: WebSocket):
                     if stream and recognizer:
                         print(f"[INFO main] Client disconnected (code={data.get('code')}). Flushing final transcript...")
                         final = finalize_stream(stream, recognizer)
-                        await websocket.send_json({"final": final})
+                        try:
+                            await websocket.send_json({"final": final})
+                        except (WebSocketDisconnect, RuntimeError):
+                            pass
                     break
                 continue
 
@@ -95,6 +99,13 @@ async def websocket_endpoint(websocket: WebSocket):
         print(f"[ERROR main] Unexpected exception: {e}")
         if stream and recognizer:
             final = finalize_stream(stream, recognizer)
-            await websocket.send_json({"final": final})
-        await websocket.close()
-        print("[INFO main] WebSocket closed, cleanup complete.")
+            try:
+                await websocket.send_json({"final": final})
+            except (WebSocketDisconnect, RuntimeError):
+                pass
+        # Ensure connection is closed
+        try:
+            await websocket.close()
+        except:
+            pass
+        print("[INFO main] WebSocket closed, cleanup complete.")