feat: Add album management functionality with new data model, repository, service, API, and generation integration.

repos/generation_repo.py

@@ -40,7 +40,7 @@ class GenerationRepo:
             generations.append(Generation(**generation))
         return generations
 
-    async def count_generations(self, character_id: Optional[str] = None, status: Optional[GenerationStatus] = None) -> int:
+    async def count_generations(self, character_id: Optional[str] = None, status: Optional[GenerationStatus] = None, album_id: Optional[str] = None) -> int:
         args = {}
         if character_id is not None:
             args["linked_character_id"] = character_id
@@ -48,5 +48,21 @@ class GenerationRepo:
             args["status"] = status
         return await self.collection.count_documents(args)
 
+    async def get_generations_by_ids(self, generation_ids: List[str]) -> List[Generation]:
+        object_ids = [ObjectId(gen_id) for gen_id in generation_ids if ObjectId.is_valid(gen_id)]
+        res = await self.collection.find({"_id": {"$in": object_ids}}).to_list(None)
+        generations: List[Generation] = []
+        
+        # Maintain order of generation_ids
+        gen_map = {str(doc["_id"]): doc for doc in res}
+        
+        for gen_id in generation_ids:
+            doc = gen_map.get(gen_id)
+            if doc:
+                doc["id"] = str(doc.pop("_id"))
+                generations.append(Generation(**doc))
+                
+        return generations
+
     async def update_generation(self, generation: Generation, ):
         res = await self.collection.update_one({"_id": ObjectId(generation.id)}, {"$set": generation.model_dump()})