feat: SuperAdmin bootstrap, i18n sync fix and AssetAssignment ORM fix

- Fixed AttributeError in User model (added region_code, preferred_language)
- Fixed InvalidRequestError in AssetAssignment (added organization relationship)
- Configured STATIC_DIR for translation sync
- Applied Alembic migrations for user schema updates

backend/app/models/__init__.py

@@ -11,8 +11,10 @@ from .address import Address, GeoPostalCode, GeoStreet, GeoStreetType
 from .gamification import PointRule, LevelConfig, UserStats, Badge, UserBadge, Rating, PointsLedger
 from .system_config import SystemParameter
 from .document import Document
+from .translation import Translation  # <--- HOZZÁADVA
 from .core_logic import SubscriptionTier, OrganizationSubscription, CreditTransaction, ServiceSpecialty
 from .history import AuditLog, VehicleOwnership
+from .security import PendingAction  # <--- HOZZÁADVA
 
 # Aliasok
 Vehicle = Asset
@@ -26,7 +28,8 @@ __all__ = [
     "AssetEvent", "AssetFinancials", "AssetTelemetry", "AssetReview", "ExchangeRate",
     "Address", "GeoPostalCode", "GeoStreet", "GeoStreetType", "PointRule", 
     "LevelConfig", "UserStats", "Badge", "UserBadge", "Rating", "PointsLedger",
-    "SystemParameter", "Document", "SubscriptionTier", "OrganizationSubscription",
+    "SystemParameter", "Document", "Translation", "PendingAction",  # <--- BŐVÍTVE
+    "SubscriptionTier", "OrganizationSubscription",
     "CreditTransaction", "ServiceSpecialty", "AuditLog", "VehicleOwnership",
     "Vehicle", "UserVehicle", "VehicleCatalog", "ServiceRecord"
 ]