Add privilege management system with related migrations and guards

- Introduced a new `PrivilegesModule` to manage user privileges and access control.
- Added `RequirePrivilege` decorator to enforce privilege checks on controller handlers.
- Implemented `PrivilegesGuard` to handle authorization based on user privileges.
- Created database migrations for `privileges`, `privilege_keys`, and `privilege_details` tables.
- Updated user model to include `is_superadmin` field for enhanced access control.
- Added unit tests for the new privileges functionality and guards to ensure correct behavior.

src/modules/auth/auth.controller.ts

@@ -16,6 +16,8 @@ import type { AuthUser } from '../../common/auth/auth-user';
 import { CurrentUser } from '../../common/decorators/current-user.decorator';
 import { Public } from '../../common/decorators/public.decorator';
 import { BEARER_AUTH_NAME } from '../../common/swagger/setup-swagger';
+import { PrivilegesService } from '../privileges/privileges.service';
+import { UsersService } from '../users/users.service';
 import { AuthService } from './auth.service';
 import {
   LoginDto,
@@ -28,7 +30,11 @@ import {
 @ApiTags('auth')
 @Controller('auth')
 export class AuthController {
-  constructor(private readonly authService: AuthService) {}
+  constructor(
+    private readonly authService: AuthService,
+    private readonly usersService: UsersService,
+    private readonly privilegesService: PrivilegesService,
+  ) {}
 
   @Public()
   @Throttle({ default: { limit: 5, ttl: 60_000 } })
@@ -87,7 +93,32 @@ export class AuthController {
   @ApiOperation({ summary: 'Get the current authenticated user' })
   @ApiOkResponse({ type: MeResponseDto })
   @ApiUnauthorizedResponse({ description: 'Missing or invalid access token' })
-  me(@CurrentUser() user: AuthUser): MeResponseDto {
-    return { id: user.id, username: user.username };
+  async me(@CurrentUser() user: AuthUser): Promise<MeResponseDto> {
+    const full = await this.usersService.findById(user.id);
+    const isSuperadmin = full?.isSuperadmin ?? user.isSuperadmin;
+    if (!full?.privilegeId) {
+      return {
+        id: user.id,
+        username: user.username,
+        isSuperadmin,
+        privilege: null,
+        permissions: {},
+      };
+    }
+
+    const privilege = await this.privilegesService.findPrivilegeSummary(
+      full.privilegeId,
+    );
+    const permissions = privilege
+      ? await this.privilegesService.getPermissionsMap(privilege.id)
+      : {};
+
+    return {
+      id: user.id,
+      username: user.username,
+      isSuperadmin,
+      privilege,
+      permissions,
+    };
   }
 }