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/user_projection_sync_service_test.go

@@ -48,12 +48,12 @@ func TestUserProjectionSyncService_ReconcileReplacesProjectionFromKratos(t *test
 	kratos.On("ListIdentities", ctx).Return([]KratosIdentity{
 		{
 			ID: "00000000-0000-0000-0000-000000000101",
-			Traits: map[string]interface{}{
+			Traits: map[string]any{
 				"email":        "one@example.com",
 				"name":         "One",
 				"phone_number": "+821012345678",
 				"companyCode":  "saman",
-				"companyCodes": []interface{}{"saman", "group-a"},
+				"companyCodes": []any{"saman", "group-a"},
 				"tenant_id":    tenantID,
 				"department":   "DX",
 				"customAttr":   "kept",
@@ -101,7 +101,7 @@ func TestMapKratosIdentityToLocalUserPreservesArchivedStatus(t *testing.T) {
 	user := MapKratosIdentityToLocalUser(KratosIdentity{
 		ID:    "00000000-0000-0000-0000-000000000201",
 		State: domain.UserStatusArchived,
-		Traits: map[string]interface{}{
+		Traits: map[string]any{
 			"email": "archived@example.com",
 			"name":  "Archived User",
 		},