Refactor code structure for improved readability and maintainability

app/repositories/base.py

@@ -72,18 +72,22 @@ class BaseRepository[ModelType]:
             logger.exception("Failed to get all %s", self.model.__name__)
             raise
 
-    async def create(self, entity_data: dict[str, Any]) -> ModelType:
+    async def create(self, entity_data: dict[str, Any] | ModelType) -> ModelType:
         """Create a new entity.
 
         Args:
-            entity_data: Dictionary of entity data
+            entity_data: Dictionary of entity data or model instance
 
         Returns:
             The created entity
 
         """
         try:
-            entity = self.model(**entity_data)
+            if isinstance(entity_data, dict):
+                entity = self.model(**entity_data)
+            else:
+                # Already a model instance
+                entity = entity_data
             self.session.add(entity)
             await self.session.commit()
             await self.session.refresh(entity)