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

server/scripts/check_db_v2.js

@@ -0,0 +1,11 @@
+const sqlite3 = require('better-sqlite3');
+const db = new sqlite3('server/data/metadata.db');
+try {
+    const results = db.prepare("SELECT * FROM model_configs WHERE modelId = 'text-embedding-v4'").all();
+    console.log('Results for text-embedding-v4:', JSON.stringify(results, null, 2));
+
+    const count = db.prepare("SELECT COUNT(*) as cnt FROM model_configs").get();
+    console.log('Total model configs:', count.cnt);
+} catch (e) {
+    console.error(e.message);
+}