feat：替换 Dify 为自建 RAG去实现

1、修复了若干无权限时的失败提示语
2、新增了一个生成后续建议问题的功能
3、重构了知识问答部分的权限管理模块
4、修复了若干渲染不恰当的样式渲染

app/api/dify-chat/chat.ts

@@ -159,6 +159,11 @@ export const difyClient = {
 
             return { result: 'success' };
         } catch (error: any) {
+            // 权限不足等明确错误需要抛出，不能吞掉
+            if (error.message?.includes('403') || error.message?.includes('401')) {
+                throw error;
+            }
+            // 网络超时等不确定错误才降级为成功（Dify 可能已执行删除）
             console.warn('[Dify Chat] 删除会话请求失败，但可能已成功删除:', error.message);
             return { result: 'success' };
         }

app/api/dify-chat/client.ts

@@ -241,9 +241,14 @@ export async function deleteConversation(id: string): Promise<{ result: string }
  * console.log('开场白:', opening_statement);
  * ```
  */
-export async function fetchAppParams(): Promise<AppParametersResponse> {
-    const url = `${API_URL}/parameters`;
-    console.log('⚙️ [Dify Client] 获取应用参数:', { url });
+export async function fetchAppParams(appId?: string): Promise<AppParametersResponse> {
+    const params = new URLSearchParams();
+    if (appId) {
+        params.append('app_id', appId);
+    }
+
+    const url = params.toString() ? `${API_URL}/parameters?${params}` : `${API_URL}/parameters`;
+    console.log('⚙️ [Dify Client] 获取应用参数:', { url, appId });
 
     try {
         const response = await axios.get<AppParametersResponse>(url, {

app/api/dify-chat/types.ts

@@ -365,6 +365,7 @@ export interface MessageEnd {
     metadata?: {
         annotation_reply?: any;
         retriever_resources?: RetrieverResource[];
+        suggested_questions?: string[];
         usage?: {
             prompt_tokens: number;
             completion_tokens: number;

app/api/v3/dify/area-datasets.ts

@@ -55,7 +55,6 @@ export interface AreasResponse {
 
 export interface CreateDatasetRequest {
   area: string;
-  dataset_id: string;
   dataset_name: string;
   dataset_description?: string;
   is_default?: boolean;