fix: resolve CI failures

- Fix gofmt formatting issue in user_service.go
- Remove unused sql field from userAttributeValueRepository
- Update ListWithFilters signature in test stubs to match interface
- Remove Wechat field from test user data

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/internal/service/admin_service_delete_test.go

@@ -66,7 +66,7 @@ func (s *userRepoStub) List(ctx context.Context, params pagination.PaginationPar
 	panic("unexpected List call")
 }
 
-func (s *userRepoStub) ListWithFilters(ctx context.Context, params pagination.PaginationParams, status, role, search string) ([]User, *pagination.PaginationResult, error) {
+func (s *userRepoStub) ListWithFilters(ctx context.Context, params pagination.PaginationParams, filters UserListFilters) ([]User, *pagination.PaginationResult, error) {
 	panic("unexpected ListWithFilters call")
 }