fix: properly handle repository errors and remove unused hash field

- fix: wrap errors from sessionRepo.Delete, credentialRepo operations
  with internal error context in Logout, ListPasskeys, and RevokePasskey
- fix: remove Hash field from fileInfoResponse DTO (unused)

internal/service/auth.go

@@ -162,7 +162,10 @@ func (s *AuthService) Logout(ctx context.Context, refreshTokenStr string) error
 		return model.NewInternalError("find session", err)
 	}
 
-	return s.sessionRepo.Delete(ctx, session.ID)
+	if err := s.sessionRepo.Delete(ctx, session.ID); err != nil {
+		return model.NewInternalError("delete session", err)
+	}
+	return nil
 }
 
 // CreatePasskey creates a new app passkey for the authenticated user.
@@ -227,7 +230,11 @@ func (s *AuthService) LoginWithPasskey(ctx context.Context, tokenStr string) (*T
 
 // ListPasskeys returns all app passkeys for a user.
 func (s *AuthService) ListPasskeys(ctx context.Context, userID string) ([]model.Credential, error) {
-	return s.credentialRepo.FindByUserIDAndType(ctx, userID, "app_passkey")
+	creds, err := s.credentialRepo.FindByUserIDAndType(ctx, userID, "app_passkey")
+	if err != nil {
+		return nil, model.NewInternalError("list passkeys", err)
+	}
+	return creds, nil
 }
 
 // RevokePasskey deletes an app passkey owned by the user.
@@ -244,7 +251,10 @@ func (s *AuthService) RevokePasskey(ctx context.Context, userID, credID string)
 		return model.NewPermissionDeniedError("access denied", model.ErrForbidden)
 	}
 
-	return s.credentialRepo.Delete(ctx, credID)
+	if err := s.credentialRepo.Delete(ctx, credID); err != nil {
+		return model.NewInternalError("delete credential", err)
+	}
+	return nil
 }
 
 // AuthenticateAccessToken validates an access token and returns the active user principal.