fix(youtube): correct extractor-args separator, soften worker recycling, retry video upload

EXTRACTOR_ARGS used ':' instead of ';' between player_client and skip
fields, so yt-dlp parsed "android:skip=translated_subs" and "hls" as
bogus player_client values and silently fell back to the web client
only, which fails the n-challenge and returns no formats.

--max-requests=1 fully restarted the gunicorn worker after every
single request, opening a race window that could drop the response
connection right after a successful download; raised to 20 with
jitter to keep the periodic-recycle safety net without doing it on
every request.

reply_video() to Telegram had no retry, so a transient httpx
transport error during upload discarded an already-downloaded video;
added the same 3-attempt retry pattern already used for the
downloader services.

youtube-downloader/app.py

@@ -133,8 +133,7 @@ YTDLP_CMD = 'yt-dlp'
 DOWNLOAD_TIMEOUT = 300
 INFO_TIMEOUT = 60
 
-PLAYER_CLIENTS = 'web,android'
-EXTRACTOR_ARGS = 'youtube:player_client=web,android:skip=translated_subs,hls'
+EXTRACTOR_ARGS = 'youtube:player_client=web,android;skip=translated_subs,hls'
 
 
 def _build_ytdlp_base_cmd() -> list: