feat: Add enhanced TTS connection error handling and diagnostics

- Add timeout handling for TTS WebSocket connections
- Improve error messages with specific diagnostic hints
- Detect when TTS service is in wrong mode (Gradio vs WebSocket)
- Guide users to set TTS_SERVICE_MODE=websocket environment variable
- Better debugging for TTS connection failures

🤖 Generated with [Claude Code](https://claude.ai/code)

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

webrtc/server/websocket_handler.py

@@ -221,12 +221,15 @@ class WebRTCHandler:
         try:
             logger.info(f"🔌 Connecting to TTS service for client {client_id}: {self.tts_websocket_url}")
             
-            # Connect to TTS WebSocket service
-            tts_ws = await websockets.connect(self.tts_websocket_url)
+            # Connect to TTS WebSocket service with timeout
+            tts_ws = await asyncio.wait_for(
+                websockets.connect(self.tts_websocket_url), 
+                timeout=10.0
+            )
             self.tts_connections[client_id] = tts_ws
             
             # Wait for connection confirmation
-            confirmation = await tts_ws.recv()
+            confirmation = await asyncio.wait_for(tts_ws.recv(), timeout=15.0)
             confirmation_data = json.loads(confirmation)
             
             if confirmation_data.get("type") == "tts_connection_confirmed":
@@ -236,8 +239,17 @@ class WebRTCHandler:
                 logger.warning(f"⚠️ Unexpected TTS confirmation: {confirmation_data}")
                 return False
                 
+        except asyncio.TimeoutError:
+            logger.error(f"❌ TTS service connection timeout - service may not be in WebSocket mode")
+            logger.info(f"💡 TTS service needs TTS_SERVICE_MODE=websocket environment variable")
+            return False
+        except websockets.exceptions.InvalidStatusCode as e:
+            logger.error(f"❌ TTS WebSocket endpoint not available: {e}")
+            logger.info(f"💡 TTS service may be running in Gradio-only mode instead of WebSocket mode")
+            return False
         except Exception as e:
             logger.error(f"❌ Failed to connect to TTS service for {client_id}: {e}")
+            logger.info(f"💡 Check if TTS service is running and configured with TTS_SERVICE_MODE=websocket")
             return False
     
     async def disconnect_from_tts_service(self, client_id: str):