I forgot to add error handling from the original Rust project, so I did that.

I also fixed the parallelism by using a Semaphore as limitedParallelism still wakes all the coroutines. Using a Semaphore only allows N permits to be handed out at once. This means that only N tasks would be running at once, given that each task takes one permit. I set N to 8 as that should not cause any throttling but still allow multiple tracks to be downloaded at once.

I also implemented better lazy fetching than the old Rust implementation. Now only pieces that must be fetched are fetched, and if they don’t need to be fetched, a StreamExtractor is never fetched. This causes a huge speed up, allowing my ~400 track playlist to be incrementally synced in 8 seconds.

Other notable quality of life features (taken from the git log):

- refactor: make output use terminal.theme.*
- refactor: make output more human readable by using title instead of youtube_playlist_id
- fix: reorder items in subtasks so that the text doesn't move everything else