feat: enhance user service with role assignment and frontend scroll-area ref support

- Updated `users.service.ts` to assign user roles dynamically based on RBAC.
- Enhanced JWT generation to include the user's role in `auth.service.ts`.
- Added `viewportRef` prop support to `ScrollArea` component in the frontend for improved flexibility.

backend/src/auth/auth.service.ts

@@ -207,6 +207,7 @@ export class AuthService {
 		const accessToken = await this.jwtService.generateJwt({
 			sub: user.uuid,
 			username: user.username,
+			role: user.role,
 		});
 
 		return {