fix: recover from container restart without losing session

When HF Space rebuilds, the in-memory _sessions dict is wiped but
WebSocket may survive through the reverse proxy. Previously this
caused 'Agent not initialized' because ws.onopen didn't fire.

Now: server sends 'request_keys' event when session is lost. Client
auto-resends keys from sessionStorage and retries the last message
after a 3-second delay for session initialization.

Author: dmpantiu

web/routes/websocket.py

@@ -98,8 +98,13 @@ async def websocket_chat(websocket: WebSocket):
                 # Get session for this connection (auto-recreate if lost)
                 session = get_session(connection_id)
                 if not session:
-                    logger.warning(f"Session lost for {connection_id[:8]}, recreating...")
-                    session = create_session(connection_id)
+                    logger.warning(f"Session lost for {connection_id[:8]}, requesting keys...")
+                    # Ask client to resend keys (e.g., after container restart)
+                    await manager.send_json(websocket, {
+                        "type": "request_keys",
+                        "reason": "Session expired, please reconnect."
+                    })
+                    continue
 
                 # Callback for streaming
                 async def stream_callback(event_type: str, content: str, **kwargs):

web/static/js/chat.js

@@ -385,6 +385,7 @@ class EurusChat {
         if (!message || !this.isConnected) return;
 
         this.addUserMessage(message);
+        this._lastSentMessage = message;
         this.ws.send(JSON.stringify({ message }));
 
         this.messageInput.value = '';
@@ -406,6 +407,22 @@ class EurusChat {
                 }
                 break;
 
+            case 'request_keys':
+                // Server lost our session (e.g., container restart) — resend keys
+                console.warn('Server requested keys:', data.reason);
+                this.removeThinkingIndicator();
+                this.autoSendSessionKeys();
+                // Retry the last message after a short delay for session init
+                if (this._lastSentMessage) {
+                    setTimeout(() => {
+                        if (this.ws && this.ws.readyState === WebSocket.OPEN) {
+                            this.ws.send(JSON.stringify({ message: this._lastSentMessage }));
+                            this.showThinkingIndicator();
+                        }
+                    }, 3000);
+                }
+                break;
+
             case 'thinking':
                 this.showThinkingIndicator();
                 break;