feat(user): support fixed UUID registration and enhance bulk import results

- Added support for fixed UUIDs during bulk registration (Search-first + ExternalID mapping)
- Implemented idempotency and visibility restoration for soft-deleted users
- Enhanced bulk upload UI to show 'New/Updated/Unchanged' status and modified fields
- Added logic to reclaim identifiers (login_id) from colliding records
- Added frontend E2E and backend unit tests for UUID integrity and conflict handling
- Fixed i18n, formatting, and mock tests to satisfy code-check
- Applied 'go fix' for 'omitzero' tags and general Go standards

backend/internal/service/tenant_service.go

@@ -336,7 +336,7 @@ func (s *tenantService) ProvisionTenantByDomain(ctx context.Context, domainName
 	}
 
 	for _, g := range groups {
-		rawConfig, ok := g.Config["autoProvisioning"].(map[string]interface{})
+		rawConfig, ok := g.Config["autoProvisioning"].(map[string]any)
 		if !ok {
 			continue
 		}
@@ -346,12 +346,12 @@ func (s *tenantService) ProvisionTenantByDomain(ctx context.Context, domainName
 			continue
 		}
 
-		mapping, ok := rawConfig["mappingRules"].(map[string]interface{})
+		mapping, ok := rawConfig["mappingRules"].(map[string]any)
 		if !ok {
 			continue
 		}
 
-		rule, ok := mapping[domainName].(map[string]interface{})
+		rule, ok := mapping[domainName].(map[string]any)
 		if !ok {
 			continue
 		}