phsl / new-api

Allow administrators to view all platform topup orders and streamline admin-only routes.

Frontend
- TopupHistoryModal: dynamically switch endpoint by role
  - Admin → GET /api/user/topup (all orders)
  - Non-admin → GET /api/user/topup/self (own orders)
- Use shared utils `isAdmin()`; keep logic centralized and DRY
- Minor UI: set admin action button theme to outline for clarity

Backend
- model/topup.go: add GetAllTopUps(pageInfo) with pagination (ordered by id desc)
- controller/topup.go: add GetAllTopUps handler returning PageInfo response
- router/api-router.go:
  - Add admin route GET /api/user/topup (AdminAuth)
  - Move POST /api/user/topup/complete to adminRoute (keeps path stable, consolidates admin endpoints)

Security/Behavior
- Admin-only endpoints now reside under the admin route group with AdminAuth
- No behavior change for regular users; no schema changes

Affected files
- model/topup.go
- controller/topup.go
- router/api-router.go
- web/src/components/topup/modals/TopupHistoryModal.jsx