发行包上传用 From 收敛结构化错误，替换重复的 map_err

- 为 GamePackageUploadError 实现 From<GamePackageUploadError> for String
- upload_staged_game_package 中三处 .map_err(|e| e.to_user_msg()) 改为 ?，Fatal 分支改为 error.into()

apps/ai-game-creator-shell/src-tauri/src/game_package_upload/runtime.rs

@@ -130,6 +130,13 @@ impl GamePackageUploadError {
     }
 }
 
+/// 上传编排对外只回一句 `String`，让 `?` 直接完成结构化错误到用户文案的收敛。
+impl From<GamePackageUploadError> for String {
+    fn from(error: GamePackageUploadError) -> Self {
+        error.to_user_msg()
+    }
+}
+
 async fn read_upload_state(
     client: &reqwest::Client,
     base_url: &str,
@@ -336,8 +343,7 @@ pub(crate) async fn upload_staged_game_package(
         request.version_id,
         &access_token,
     )
-    .await
-    .map_err(|error| error.to_user_msg())?;
+    .await?;
     if state.declared_package_bytes != 0 && state.declared_package_bytes != total_bytes {
         return Err(format!(
             "本地发行包与版本声明的体积不一致（本地 {} 字节，声明 {} 字节），请重新导出后再发布",
@@ -374,7 +380,7 @@ pub(crate) async fn upload_staged_game_package(
                     on_progress(received, total_bytes);
                     break;
                 }
-                Err(ChunkUploadError::Fatal(error)) => return Err(error.to_user_msg()),
+                Err(ChunkUploadError::Fatal(error)) => return Err(error.into()),
                 Err(ChunkUploadError::Retryable(error)) => {
                     if attempt >= CHUNK_MAX_ATTEMPTS {
                         return Err(format!(
@@ -395,8 +401,7 @@ pub(crate) async fn upload_staged_game_package(
             request.version_id,
             &access_token,
         )
-        .await
-        .map_err(|error| error.to_user_msg())?;
+        .await?;
         received = authoritative.received_bytes.min(total_bytes);
         on_progress(received, total_bytes);
     }
@@ -408,8 +413,7 @@ pub(crate) async fn upload_staged_game_package(
         &access_token,
         request.idempotency_key,
     )
-    .await
-    .map_err(|error| error.to_user_msg())?;
+    .await?;
     outcome.uploaded_bytes = total_bytes;
     Ok(outcome)
 }