fix: resolve CI failures — gofmt, unused functions, test parameter mismatches

- gofmt: user.go, config_test.go, group_handler.go, smart_retry_test.go
- Remove unused: mergeGroupIDs, resolveProxyURL, "time" import
- Fix api_contract_test.go: remove extra Sora args from NewAdminService,
  NewSettingHandler, NewAccountHandler; remove Sora field expectations
- Fix account_test_service_openai_test.go: restore test helpers

backend/internal/repository/api_key_repo.go

@@ -604,20 +604,20 @@ func userEntityToService(u *dbent.User) *service.User {
 		return nil
 	}
 	return &service.User{
-		ID:                    u.ID,
-		Email:                 u.Email,
-		Username:              u.Username,
-		Notes:                 u.Notes,
-		PasswordHash:          u.PasswordHash,
-		Role:                  u.Role,
-		Balance:               u.Balance,
-		Concurrency:           u.Concurrency,
-		Status:                u.Status,
-		TotpSecretEncrypted:   u.TotpSecretEncrypted,
-		TotpEnabled:           u.TotpEnabled,
-		TotpEnabledAt:         u.TotpEnabledAt,
-		CreatedAt:             u.CreatedAt,
-		UpdatedAt:             u.UpdatedAt,
+		ID:                  u.ID,
+		Email:               u.Email,
+		Username:            u.Username,
+		Notes:               u.Notes,
+		PasswordHash:        u.PasswordHash,
+		Role:                u.Role,
+		Balance:             u.Balance,
+		Concurrency:         u.Concurrency,
+		Status:              u.Status,
+		TotpSecretEncrypted: u.TotpSecretEncrypted,
+		TotpEnabled:         u.TotpEnabled,
+		TotpEnabledAt:       u.TotpEnabledAt,
+		CreatedAt:           u.CreatedAt,
+		UpdatedAt:           u.UpdatedAt,
 	}
 }