fix: 修正ReviewModeSelector檔案結尾換行符

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

backend/DramaLing.Api/Services/ReviewModeSelector.cs

@@ -80,4 +80,4 @@ public class ReviewModeSelector : IReviewModeSelector
             _ => 50 // 預設B1
         };
     }
-}
+}