fix(worker): 素材下载改用storage_key字段，修复file_url为URL导致下载无效文件

- AssetModel新增storage_key字段（OSS存储键）
- render_adapter _download_assets改用a.storage_key
- render_adapter BGM下载改用storage_key
- edit_plan_generation legacy路径同步修复
- generation.py BGM下载同步修复
- asset_repository映射同步更新storage_key字段
- 单元测试同步更新

packages/adapters/sqlalchemy_impl/asset_repository.py

@@ -72,6 +72,7 @@ class SQLAlchemyAssetRepository:
             file_type=(asset.mime_type.split("/")[0] if "/" in asset.mime_type else asset.mime_type),
             file_size=asset.file_size,
             file_url=asset.storage_key,
+            storage_key=asset.storage_key,
             thumbnail_url=asset.thumbnail_url,
             duration=asset.duration,
             width=asset.width,
@@ -100,6 +101,7 @@ class SQLAlchemyAssetRepository:
         model.name = asset.name
         model.file_size = asset.file_size
         model.file_url = asset.storage_key
+        model.storage_key = asset.storage_key
         model.thumbnail_url = asset.thumbnail_url
         model.duration = asset.duration
         model.width = asset.width
@@ -299,7 +301,7 @@ class SQLAlchemyAssetRepository:
             project_id=model.project_id,
             library_id=model.asset_library_id,
             name=model.name,
-            storage_key=model.file_url,
+            storage_key=model.storage_key or model.file_url,
             mime_type=mime_type,
             file_size=int(model.file_size or 0),
             thumbnail_url=model.thumbnail_url,

packages/adapters/sqlalchemy_impl/models.py

@@ -75,6 +75,8 @@ class AssetModel(Base):
     file_size = Column(Integer, nullable=False)
     # file_url: 完整可访问的 URL，用于客户端直接访问文件
     file_url = Column(String(1000), nullable=False)
+    # storage_key: OSS 存储键，用于内部下载上传
+    storage_key = Column(String(500), nullable=False, default="", server_default="")
     thumbnail_url = Column(String(1000), nullable=True)
     duration = Column(Float, nullable=True)
     width = Column(Float, nullable=True)