Add reset and filename_format translations

Add a "reset" button label and new "filename_format" + "filename_format_help" entries to multiple locale JSON files (ar, de, es, fr, hi, id, it, ja, pl, pt, ru, tr, zh). The help text documents supported yt-dlp output template variables (%(title)s, %(uploader)s, %(upload_date)s, %(resolution)s, %(id)s, %(ext)s) so the UI can accept a custom output filename format.

ytsage/languages/zh.json

@@ -57,6 +57,7 @@
     "audio_only_resolution": "仅音频"
   },
   "buttons": {
+    "reset": "重置",
     "download": "下载",
     "pause": "暂停",
     "resume": "恢复",
@@ -314,7 +315,9 @@
     "audio_format_wav": "WAV（未压缩）",
     "audio_format_opus": "Opus（高效）",
     "audio_format_m4a": "M4A（Apple）",
-    "audio_format_vorbis": "Vorbis（开放）"
+    "audio_format_vorbis": "Vorbis（开放）",
+    "filename_format": "输出文件名格式",
+    "filename_format_help": "可用变量: %(title)s, %(uploader)s, %(upload_date)s, %(resolution)s, %(id)s, %(ext)s。支持标准的 yt-dlp 输出模板语法。"
   },
   "main_ui": {
     "url_placeholder": "输入 YouTube 视频或播放列表网址",