feat(courses): add type, search, and pricing filters to org landing page

- Add Types section to the Filter sidebar with all 4 course types
- Add full-text search input centered in the hero (title + description)
- Add Pricing section (Free / Paid) based on course cost
- Compact hero prop across all 10 themes to halve vertical padding
- Children snippet support in all hero themes for the search input
- All filters are URL-driven (?types=, ?search=, ?tags=, ?pricing=)
- Full-stack: validation schema, DB queries, service, API route, server load, UI

apps/dashboard/src/lib/utils/translations/vi.json

@@ -3741,7 +3741,13 @@
     "filters": {
       "title": "Lọc theo thẻ",
       "help": "Chọn một hoặc nhiều thẻ để lọc các khóa học",
-      "empty": "Chưa có thẻ nào"
+      "empty": "Chưa có thẻ nào",
+      "tags_title": "Thẻ",
+      "types_title": "Các loại",
+      "search_placeholder": "Tìm kiếm khóa học...",
+      "pricing_title": "Định giá",
+      "pricing_free": "miễn phí",
+      "pricing_paid": "Đã trả tiền"
     }
   },
   "tags_admin": {