Function execute 

pub async fn execute<H, F, G, C>(
    plan: &Plan,
    manifest: &mut Manifest,
    albums: &mut BTreeMap<String, AlbumArt>,
    playlists: &mut BTreeMap<String, PlaylistState>,
    desired: &[Desired],
    ports: Ports<'_, H, F, G, C>,
    opts: &ExecOptions,
) -> ExecOutcome
where
    H: Http,
    F: Filesystem,
    G: Ffmpeg,
    C: Clock,

Apply plan to disk, updating manifest and albums in place, and return the outcome.

desired carries the per-clip metadata and art hashes plus the source modes that decide the preserve marker; it is indexed by clip id (and by target path, for renames) so each written entry records the right hashes and protection. albums is the album-art store, keyed by stable root id: folder-art writes and deletes record their state there rather than on the per-clip manifest. ports bundles the authenticated client and the network, disk, transcode, and backoff ports. A single clip’s failure never aborts the run, except an auth failure or a full disk, which stop it with RunStatus::AuthAborted or RunStatus::DiskFull.

The audio-producing actions (Download and Reformat) run concurrently, bounded by ExecOptions::concurrency: their slow parts (WAV render, CDN download, transcode, tag) overlap while the order-sensitive Suno API calls are serialised behind an async mutex over the shared SunoClient, keeping the adaptive limiter and JWT refresh correct. The remaining actions (retag, rename, delete, and artifact writes/deletes) then run serially in plan order.

The outcome is deterministic regardless of completion order: concurrent audio results are committed to the manifest in plan-index order, so the same plan always yields the same manifest and counts whatever the concurrency level. A per-clip failure is recorded and the run continues; only an auth failure or a full disk aborts, and it does so promptly by stopping further audio work.