Add UI tab labels to translation files

Add "tab_general", "tab_format", and "tab_file" entries to multiple ytsage/languages/*.json files to provide localized labels for the UI tabs (General, Format, File). Also include a minor formatting/newline fix in en.json.

ytsage/languages/en.json

@@ -340,7 +340,10 @@
     "audio_format_wav": "WAV (Uncompressed)",
     "audio_format_opus": "Opus (Efficient)",
     "audio_format_m4a": "M4A (Apple)",
-    "audio_format_vorbis": "Vorbis (Open)"
+    "audio_format_vorbis": "Vorbis (Open)",
+    "tab_general": "General",
+    "tab_format": "Format",
+    "tab_file": "File"
   },
   "main_ui": {
     "url_placeholder": "Enter YouTube video or playlist URL",
@@ -622,4 +625,4 @@
     "update_failed": "❌ Update failed: {error}",
     "check_failed": "Failed to check for updates. Please check your internet connection."
   }
-}
+}