chore: bump vaix-rag cache-buster gc=74 (topAdded lazy fix)

index.html

@@ -877,7 +877,7 @@
 <script defer src="/src/catalogue-ai.js?gc=36"></script>    <!-- Catalogue AI module (NL search over OCR'd Malloca 2026 catalogue) -->
 	    <script defer src="/src/catai-intro.js?v=3"></script>     <!-- What's-new auto-intro banner (giới thiệu tính năng mới tự động) -->
 	    <script defer src="/src/customers.js?gc=21"></script>    <!-- Customer list (Danh sách khách hàng) -->
-<script defer src="/src/vaix-rag.js?gc=73"></script>    <!-- V.AI STUDIO RAG Module - loads FASTER via light index; lazy galleries; spec-aware search -->
+<script defer src="/src/vaix-rag.js?gc=74"></script>    <!-- V.AI STUDIO RAG Module - loads FASTER via light index; lazy galleries; spec-aware search -->
 	    <script defer src="/src/greeting-news.js?gc=43"></script>  <!-- Greeting HOT news cards + source links -->
 	    <script defer src="/src/order-sync.js?gc=19"></script>    <!-- Order sync with V.AISTUDIO backend -->
 	    <script type="module" src="/src/app.js?gc=65"></script>