feat: Implement image thumbnail generation, storage, and API endpoints for assets, including a regeneration utility.

repos/generation_repo.py

@@ -28,7 +28,9 @@ class GenerationRepo:
                               limit: int = 10, offset: int = 10) -> List[Generation]:
         args = {}
         if character_id is not None:
-            args["character_id"] = character_id
+            args["linked_character_id"] = character_id
+        else:
+            args["linked_character_id"] = None
         if status is not None:
             args["status"] = status
         res = await self.collection.find(args).sort("created_at", -1).skip(