feat(repo): add soft-delete with status filter to file queries

File repository now filters by status=active in all query methods (FindByID, FindByUserID, FindByParentID, FindByNameAndParent).

Delete now performs soft-delete by setting status to 'user_deleted' instead of physical row deletion.

Add ListIncludeDeleted to UserRepository for admin views of all users.

Add tests: StatusFilter, SoftDelete, DeleteIdempotent, StatusFilterCount.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

internal/repository/user.go

@@ -25,6 +25,7 @@ type UserRepository interface {
 	Update(ctx context.Context, user *model.User) error
 	Delete(ctx context.Context, id string) error
 	List(ctx context.Context, offset, limit int) ([]model.User, int64, error)
+	ListIncludeDeleted(ctx context.Context, offset, limit int) ([]model.User, int64, error)
 }
 
 type userRepository struct {
@@ -130,3 +131,20 @@ func (r *userRepository) List(ctx context.Context, offset, limit int) ([]model.U
 
 	return users, total, nil
 }
+
+// ListIncludeDeleted returns all users (including soft-deleted), paginated.
+func (r *userRepository) ListIncludeDeleted(ctx context.Context, offset, limit int) ([]model.User, int64, error) {
+	var users []model.User
+	var total int64
+
+	if err := r.db.WithContext(ctx).Model(&model.User{}).Count(&total).Error; err != nil {
+		return nil, 0, err
+	}
+
+	result := r.db.WithContext(ctx).Offset(offset).Limit(limit).Find(&users)
+	if result.Error != nil {
+		return nil, 0, result.Error
+	}
+
+	return users, total, nil
+}