6bd6436c81
Add functions/yt-dlp.fish, shadowing yt-dlp to prepend sane defaults (--sponsorblock-remove all, --embed-subs, --embed-metadata, --embed-thumbnail). Each default is suppressed when the user already passes that flag, its alias (--add-metadata), its negation (--no-embed-thumbnail), the --opt=value form (--sponsorblock-remove=...), or the global --no-sponsorblock kill. User args pass through last so an explicit flag wins on precedence. Gated as a C1 opinionated alias; falls back to bare `command yt-dlp` when disabled. Register yt-dlp as a recommended (rec tier) dependency in the fish-deps catalog and document the function (§5.13) and dependency in the SSOT and index.