move default yt-dlp args to config.json YTDLP_ARGS for user override

- Move hardcoded default args from Python to config.json YTDLP_ARGS
- Add get_ytdlp_args() function to read from YTDLP_ARGS env var
- Keep format arg with max_size in code (depends on YTDLP_MAX_SIZE)
- YTDLP_ARGS can be overridden as JSON array in environment

archivebox/plugins/ytdlp/config.json

@@ -41,20 +41,31 @@
       "type": "array",
       "items": {"type": "string"},
       "default": [
+        "--restrict-filenames",
+        "--trim-filenames", "128",
+        "--write-description",
         "--write-info-json",
         "--write-thumbnail",
         "--write-sub",
-        "--embed-subs",
-        "--write-auto-sub"
+        "--write-auto-subs",
+        "--convert-subs=srt",
+        "--yes-playlist",
+        "--continue",
+        "--no-abort-on-error",
+        "--ignore-errors",
+        "--geo-bypass",
+        "--add-metadata",
+        "--no-progress",
+        "-o", "%(title)s.%(ext)s"
       ],
       "x-aliases": ["MEDIA_ARGS"],
-      "description": "Default yt-dlp arguments"
+      "description": "Default yt-dlp arguments (override to customize behavior)"
     },
     "YTDLP_EXTRA_ARGS": {
       "type": "string",
       "default": "",
       "x-aliases": ["MEDIA_EXTRA_ARGS"],
-      "description": "Extra arguments for yt-dlp (space-separated)"
+      "description": "Extra arguments for yt-dlp (space-separated, appended after YTDLP_ARGS)"
     }
   }
 }