feat: add image management functionality

- Implemented image folder repository with CRUD operations.
- Added image reference repository for managing image references to articles.
- Created image repository for handling image assets, including listing, inserting, updating, and deleting images.
- Introduced image usage repository to track storage usage and quotas for tenants.
- Added SQL queries for image assets, folders, references, and usage.
- Developed image handler for HTTP endpoints to manage images and folders.
- Created database migration scripts for image-related tables and structures.

apps/admin-web/src/layouts/AppShell.vue

@@ -5,6 +5,7 @@ import {
   GlobalOutlined,
   RadarChartOutlined,
   SearchOutlined,
+  PictureOutlined,
   DownOutlined,
   LogoutOutlined,
   TranslationOutlined,
@@ -95,6 +96,7 @@ const navSections = computed(() => [
     title: t("nav.contentManagement"),
     items: [
       { key: "/knowledge", label: t("nav.knowledge"), icon: BookOutlined },
+      { key: "/images", label: t("nav.images"), icon: PictureOutlined },
     ],
   },
 ]);