feat: full FrontOffice updates - discount store, blog, payment gateway, UI improvements

- Discount store pages (products, cart, orders, order detail)
- Blog pages and services
- Payment gateway callback page
- AppImage component, EmptyState, LoadingState, PageHeader
- DiscountCartService, DiscountOrderService, DiscountProductService
- BlogCategoryService, BlogPostService, SitePageService, ImageCacheService
- PhoneVerifyForm component
- Profile Hub page
- UI/UX improvements across all pages
- landing.js for homepage
- Config and routing updates

src/FrontOffice.Main/appsettings.Staging.json

@@ -1,6 +1,6 @@
 {
   "GwUrl": "https://cms.se.kbs1.ir",
-  "DownloadUrl": "https://dl.afrino.co",
+  "DownloadUrl": "",
   "EncryptionSettings": {
     "Key": "kmcQ3XTmH4mrdh8VHziuscyf8LLYjG//Kyni81nH/0E=",
     "IV": "1wyF3Tt142MOkCpIyCxh/g=="