Ytdl-sub

[BACKEND] Validate override variable names (845)

Validate as early as possible whether override names are invalid, to prevent confusing downstream errors

[BACKEND][HUGE] Function Support in variable syntax (838)

A complete gutting of the internals of ytdl-sub to support functions in our variable syntax, in addition to being able to access a yt-dlp entry's .info.json fields using functions. Functionally, ytdl-sub should still look and behave the same from a user-perspective.

With so many lines of code changed (+8927, -2708), no doubt there will be new issues. Please make a GH issue or reach out on Discord if your config/subscriptions break in any way/shape/form.

Details on how to use function support will come soon in the form of proper documentation in our readthedocs.

[BUGFIX] Use proper extractor key for download archive (840)

For less popular sites, ytdl-sub's custom download archive was not working. This was because we weren't using the right extraction key (though it still worked for YouTube, Bandcamp, Soundcloud, and others). This bugfix should now exactly match yt-dlp's and never be a problem again.

Huge thanks to Svagtlys for root-causing this 🤝

[BUGFIX] file_convert output file deleted (822)

file_convert.py:modify_entry() deletes the converted output file if the output and input file names are identical. Reordered the file deletion to avoid.

Thanks OmarAhmadyar !

[FEATURE] Add `output_options.keep_max_files` to limit number of downloads per subscription (820)

Adds a new mechanism to limit subscriptions' number of videos to an explicit number (only supported date ranges prior to this).

Example usage:

output_options:
keep_max_files: 10

will only keep 10 videos at max.

In addition:
- `keep_max_files` is bundled into the `Only Recent` preset and can be used via setting the `only_recent_max_files` override variable (see examples or README for usage).
- Changed the `date_range` variable name to `only_recent_date_range` for more clarity. Usage of `date_range` will continue to work.

[BACKEND] Upgrade yt-dlp to 2023.11.16 (817)