feat: implement QuestionBank CRUD with pagination and template query

- Add pagination support to findAll (page, limit query params)
- Add findByTemplateId method to service
- Add GET /by-template/:templateId endpoint to controller
- Service already includes CRUD for QuestionBank and QuestionBankItem

web/services/ragService.ts

@@ -0,0 +1,41 @@
+export interface RagSearchResult {
+  content: string;
+  fileName: string;
+  score: number;
+  chunkIndex: number;
+}
+
+export interface RagResponse {
+  searchResults: RagSearchResult[];
+  sources: string[];
+  ragPrompt: string;
+  hasRelevantContent: boolean;
+}
+
+export const ragService = {
+  
+  async search(query: string, settings: any, authToken: string): Promise<RagResponse> {
+    try {
+      const response = await fetch('/api/knowledge-bases/rag-search', {
+        method: 'POST',
+        headers: {
+          'Content-Type': 'application/json',
+          'Authorization': `Bearer ${authToken}`,
+        },
+        body: JSON.stringify({ query, settings }),
+      });
+
+      if (!response.ok) {
+        const errorData = await response.text();
+        console.error('RAG search error:', response.status, errorData);
+        throw new Error(`RAG search failed: ${response.status} - ${errorData}`);
+      }
+
+      const result = await response.json();
+      return result;
+    } catch (error) {
+      console.error('RAG service error:', error);
+      throw error;
+    }
+  },
+};