podsync

Added min_age option for video filtering (complementing max_age). Fixed several playlist-related issues: correct author and title for playlist feeds, correct playlist thumbnail via yt-dlp, smarter playlist date handling (only use playlist added date if newer than video publish date), and skipping unreleased premiere and currently-airing videos. Updated yt-dlp permissions and location to support self-updating. Updated Alpine Linux to 3.21, Go to 1.24, and bumped numerous dependencies including golang.org/x/net (0.11.0→0.38.0, spanning multiple patch releases), oauth2, protobuf, and google.golang.org/api.