feat: complete Day 21-24 knowledge base features

- Day 21-22: fix CORS and file upload issues
- Day 23-24: implement @knowledge base search and conversation integration
- Backend: integrate Dify RAG into conversation system
- Frontend: load knowledge base list and @ reference feature

frontend/src/pages/AgentChatPage.tsx

@@ -8,10 +8,12 @@ import MessageList from '../components/chat/MessageList'
 import MessageInput from '../components/chat/MessageInput'
 import ModelSelector, { type ModelType } from '../components/chat/ModelSelector'
 import { useProjectStore } from '../stores/useProjectStore'
+import { useKnowledgeBaseStore } from '../stores/useKnowledgeBaseStore'
 
 const AgentChatPage = () => {
   const { agentId } = useParams()
   const { currentProject } = useProjectStore()
+  const { knowledgeBases, fetchKnowledgeBases } = useKnowledgeBaseStore()
   
   // 智能体相关状态
   const [agent, setAgent] = useState<AgentConfig | null>(null)
@@ -26,9 +28,6 @@ const AgentChatPage = () => {
   // 消息发送状态
   const [sending, setSending] = useState(false)
   const [streamingContent, setStreamingContent] = useState('')
-  
-  // 知识库（预留）
-  const [knowledgeBases] = useState([])
 
   // 加载智能体配置
   useEffect(() => {
@@ -56,6 +55,11 @@ const AgentChatPage = () => {
     fetchAgent()
   }, [agentId])
 
+  // 加载知识库列表
+  useEffect(() => {
+    fetchKnowledgeBases()
+  }, [])
+
   // 创建或加载对话
   useEffect(() => {
     const initConversation = async () => {
@@ -267,4 +271,3 @@ const AgentChatPage = () => {
 }
 
 export default AgentChatPage
-