[dev][Admin] Member Management - 1 FE + 1 BE

[pankinkun]

Member Management (1 FE)

• List all members displaying name, email, role (dropdown), payment (dropdown), link to member profile
• "Save" button: PUT /api/user

Handle changes (1 BE) Get all members and return as an array GET /api/user

Update user PATCH /api/user/[userId]