playlists: make the writes actually leave the browser

Reported from a phone: signing in with the same account showed no
playlists. syncWith was called from exactly one place in the interface,
so creating a playlist, deleting one, removing a track and saving the
queue all wrote to IndexedDB and stopped there. The store pushes itself
now, coalesced, so a new mutation cannot forget to.

Silence was the real defect. The node audited only successes, so a
refusal left no trace and user_blob_list none at all; the background
push swallowed its reason; the interface said nothing. All three report
now, and "Sync now" says what happened either way.

An unreadable blob on a node was treated as a fetch failure and returned
before the push — permanent, once the node held anything. It is an
absence: the client is the authority, and it gets overwritten.

A sign-in reconciles whatever this browser already holds, a pending push
is flushed when the page goes away, and a push that did not land is
retried once.

no_key is spelled out: a client that signs in with its remembered device
key only ever has a bundle key persisted before the playlist subkey
existed, and an AES handle is non-extractable.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

0 files changed, 0 insertions, 0 deletions