FIX /admin/settings/apis - HTTP 500 - 2026-09-25

Muc tieu:
- Trang /admin/settings/apis khong bi 500 khi database con du lieu ApiConfig cu/hong kieu.
- Khong doi API card mac dinh, PRJ key hay link cron/callback hien co.

Da sua:
1) app/Http/Controllers/Admin/Settings/ApiController.php
- Khoi tao day du cac bien config ma Blade can.
- Chuan hoa ApiConfig value ve array neu du lieu DB cu la NULL, chuoi rong hoac JSON scalar.
- Chuan hoa charging_card.fees, notification_routing.channels va cac mang FPayment.
- Tranh TypeError khi Blade doc config cu khong dung cau truc.

2) resources/views/admin/settings/apis.blade.php
- Doc Telegram config trong try/catch va ep ve array an toan.
- Feature Discord/multi-channel duoc doc an toan mot lan, loi feature/license khong lam chet trang.
- Web2m token cu/plaintext/ciphertext hong van khong lam 500.
- Dung App\\Helpers\\Helper truc tiep de khong phu thuoc alias cache cu.

3) resources/views/admin/layouts/partials/sidebar.blade.php
- Link API Keys dung URL truc tiep /admin/settings/apis, khong phu thuoc named-route cache.

Giu nguyen:
- API card: https://naptaikhoan.com/chargingws/v2
- PRJ key: TDSBPi
- Cac endpoint auto-card/card-callback/run-all dang co trong source.

Kiem tra local:
- PHP syntax ApiController: OK
- Blade compile apis.blade.php: OK
- Blade compile sidebar.blade.php: OK

Neu hosting da tung cache view/route cu:
- cPanel File Manager > storage/framework/views: xoa cac file .php cache (giu .gitignore neu co).
- bootstrap/cache: chi xoa file routes-*.php neu co; KHONG xoa packages.php/services.php.
