fix: 修复重复 URL 添加被静默跳过且无提示的问题

app/ytdl.py

@@ -867,7 +867,12 @@ class DownloadQueue:
             key = entry.get('webpage_url') or entry['url']
             if not self.queue.exists(key):
                 dl = DownloadInfo(video_id, entry.get('title') or video_id, key, quality, format, folder, custom_name_prefix, error, entry, playlist_item_limit)
-                await self.__add_download(dl, auto_start)
+                result = await self.__add_download(dl, auto_start)
+                if result:
+                    # __add_download reports a skipped duplicate or an error
+                    # (e.g. {'status': 'ok', 'msg': 'Download already exists'});
+                    # surface that instead of an unconditional success.
+                    return result
             return {'status': 'ok'}
         return {'status': 'error', 'msg': f'Unsupported resource "{etype}"'}