Remove and reorder unused imports across the project for cleaner and more consistent code structure

backend/app/models/__init__.py

@@ -5,12 +5,11 @@ Imports all models to ensure they're registered with SQLAlchemy.
 # First import Base to avoid circular imports
 from app.core.database import Base
 from .base import TimestampMixin, UUIDMixin
-
+from .organization import Organization
 # Import models
 from .user import User
-from .user_session import UserSession
-from .organization import Organization
 from .user_organization import UserOrganization, OrganizationRole
+from .user_session import UserSession
 
 __all__ = [
     'Base', 'TimestampMixin', 'UUIDMixin',