`mux:mirror` Artisan Command

Upload local videos to Mux, and remove orphaned Mux videos.

Runs mux:upload and mux:prune in sequence.

sh

# Sync local assets to Mux
php artisan mux:mirror

# Sync local assets to Mux, reupload existing videos
php artisan mux:mirror --force

# Perform a trial run and print a list of affected files
php artisan mux:mirror --dry-run