fix: 完成下载并发与翻译交接链路

adapters/src/official/mod.rs

@@ -4,11 +4,16 @@
 //! client endpoints. Mirror-specific layers such as `bluearchive.cafe` or
 //! `text=jp/voice=jp/media=jp` are intentionally excluded.
 
+pub mod backend;
 pub mod game_main_config;
 pub mod inventory;
 pub mod launcher;
 pub mod yostar_jp;
 
+pub use backend::{
+    destination_under_root, DownloadUrlMapper, OfficialResourceBackend, PlatformCatalogInput,
+    YostarJpBackend,
+};
 pub use game_main_config::YostarJpGameMainConfig;
 pub use inventory::{
     YostarJpDownloadInventory, YostarJpPlatformCatalogInventory, YostarJpPlatformDownloadInventory,