Updated backend and frontend to use UUID strings instead of integers for user and role IDs
to match PostgreSQL database schema (UUID type).
Backend changes:
- Updated User and UserPublic interfaces: id and role_id now string (UUID)
- Updated JwtPayload: userId and roleId now string
- Updated user validators: role_id validation changed from number to UUID string
- Removed parseInt() calls in user controller (getUserById, updateUser, deleteUser, changePassword)
- Updated all user service function signatures to accept string IDs
- Updated create() and update() functions to accept role_id as string
Frontend changes:
- Updated User interface in users API: role_id is string
- Updated CreateUserInput and UpdateUserInput: role_id is string
- Added role filter in UsersPage sidebar
- Removed number conversion logic (parseInt)
This fixes the "invalid input syntax for type uuid" error when creating/updating users.