fix: propagate real message IDs via SSE and fix regenerate model parameter

- Add message_id and user_message_id to SSE done events so frontend
  can replace temp IDs with real DB IDs, fixing "消息不存在" on regenerate
- Replace Body(default=None) with RegenerateRequest Pydantic model for
  proper JSON body parsing, fixing 422 Unprocessable Content
- Frontend always sends model in regenerate request body
- Pass selected model through message-item → regenerateMessage chain
- Various UI refinements to chat sidebar, quick questions, and layout

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

web/src/lib/api.ts

@@ -40,39 +40,25 @@ async function apiRequest<T>(
   };
 
   try {
-    console.log(`🌐 API请求: ${endpoint}`, { url, headers: defaultHeaders });
     const response = await fetch(url, config);
-    console.log(`📡 API响应: ${endpoint}`, { status: response.status, ok: response.ok });
-    
+
     if (!response.ok) {
-      // 401错误：token无效或过期，跳转到登录页
       if (response.status === 401) {
-        console.warn("🚨 收到401错误，token可能无效或过期");
-        console.log("🔍 当前路径:", window.location.pathname);
-        console.log("🔍 当前token:", localStorage.getItem("auth_token") ? "存在" : "不存在");
-        
-        // 清除本地存储的token
         localStorage.removeItem("auth_token");
-        
-        // 只在非登录/注册页面才跳转，避免死循环
-        if (typeof window !== 'undefined' && 
+        if (typeof window !== 'undefined' &&
             !window.location.pathname.includes('/login') &&
             !window.location.pathname.includes('/register')) {
-          console.warn("🔄 Token无效或已过期，跳转到登录页");
-          // 使用replace而不是href，避免在历史记录中留下当前页面
           window.location.replace("/login");
         }
-        
         throw new Error("认证已过期，请重新登录");
       }
-      
+
       const errorData = await response.json().catch(() => ({}));
       throw new Error(errorData.detail || `HTTP ${response.status}`);
     }
 
     return await response.json();
   } catch (error) {
-    console.error(`API请求失败 ${endpoint}:`, error);
     throw error;
   }
 }
@@ -443,7 +429,7 @@ export const chatAPI = {
     knowledgeBaseIds?: string[],
     signal?: AbortSignal,
     onChunk?: (chunk: string) => void,
-    onComplete?: (sessionId: number) => void,
+    onComplete?: (sessionId: number, messageId?: number, userMessageId?: number) => void,
     onError?: (error: string) => void,
     onStatus?: (status: string) => void,
     onThinking?: (step: { step: string; message: string; details?: Record<string, any>; timestamp?: string }) => void,
@@ -598,8 +584,8 @@ export const chatAPI = {
                 console.log("[DEBUG-STREAM] 接收chunk:", data.content);
                 onChunk?.(data.content);
               } else if (data.type === "done") {
-                console.log("[DEBUG-STREAM] 流式完成, session_id:", data.session_id);
-                onComplete?.(data.session_id);
+                console.log("[DEBUG-STREAM] 流式完成, session_id:", data.session_id, "message_id:", data.message_id, "user_message_id:", data.user_message_id);
+                onComplete?.(data.session_id, data.message_id, data.user_message_id);
               } else if (data.error) {
                 console.log("[DEBUG-STREAM] 流式错误:", data.error);
                 onError?.(data.error);
@@ -685,13 +671,14 @@ export const chatAPI = {
     });
   },
 
-  async regenerateMessage(messageId: number) {
+  async regenerateMessage(messageId: number, model?: string) {
     return apiRequest<{
       message: string;
       new_message_id: number;
       content: string;
     }>(`/chat/messages/${messageId}/regenerate`, {
       method: "POST",
+      body: JSON.stringify({ model: model || null }),
     });
   },