feat: Implement knowledge import feature for characters

- Added KnowledgeImport page for importing character knowledge from URLs.
- Integrated URL validation and error handling for unsupported websites.
- Created API endpoints for importing content from URLs and retrieving character knowledge.
- Enhanced VectorStoreService with logging and error handling for vector memory storage.
- Updated frontend to display knowledge sources and manage them effectively.
- Added support for fetching recent character knowledge as a fallback in similarity searches.
- Updated OpenAPI documentation to reflect new import functionality.

apps/frontend/src/pages/Chat.tsx

@@ -5,6 +5,7 @@ import { useCharacterStore } from '../stores/characterStore';
 import { useAuthStore } from '../stores/authStore';
 import type { Message } from '../types';
 import { io, Socket } from 'socket.io-client';
+import { chatControllerSendMessage } from '../api/generated/conversations/conversations';
 
 const WS_URL = (import.meta.env as unknown as ImportMetaEnv).VITE_WS_URL || 'http://localhost:3000';
 
@@ -26,6 +27,7 @@ export function Chat() {
   
   const [message, setMessage] = useState('');
   const [streamingContent, setStreamingContent] = useState('');
+  const [socketConnected, setSocketConnected] = useState(false);
   const messagesEndRef = useRef<HTMLDivElement>(null);
   const socketRef = useRef<Socket | null>(null);
 
@@ -42,6 +44,17 @@ export function Chat() {
 
     socket.on('connect', () => {
       console.log('Connected to chat server');
+      setSocketConnected(true);
+    });
+
+    socket.on('disconnect', () => {
+      console.log('Disconnected from chat server');
+      setSocketConnected(false);
+    });
+
+    socket.on('connect_error', (err) => {
+      console.error('Socket connection error:', err.message);
+      setSocketConnected(false);
     });
 
     socket.on('message_chunk', (data: { conversationId: string; chunk: { content: string } }) => {
@@ -111,11 +124,30 @@ export function Chat() {
     setStreamingContent('');
     setStreaming(true);
 
-    // Send via socket for streaming
-    socketRef.current?.emit('send_message', {
-      conversationId,
-      content,
-    });
+    // Check if socket is connected, otherwise fallback to HTTP
+    if (socketRef.current?.connected) {
+      socketRef.current.emit('send_message', {
+        conversationId,
+        content,
+      });
+    } else {
+      // Fallback to HTTP API when socket is not connected
+      try {
+        const result = await chatControllerSendMessage(conversationId, { content });
+        
+        // Add messages to the conversation
+        if (result.userMessage) {
+          addMessage(result.userMessage as Message);
+        }
+        if (result.assistantMessage) {
+          addMessage(result.assistantMessage as Message);
+        }
+        setStreaming(false);
+      } catch (error) {
+        console.error('Failed to send message:', error);
+        setStreaming(false);
+      }
+    }
   };
 
   const handleLogout = () => {