The user-data cache is keyed by server instance
(`iptvnator-server:cache:<instanceId>:<namespace>`): a tab still open on
the old backend after BACKEND_URL changed no longer writes over the new
server's cache, which the new tab's next edit would have sent there.
claimCache also removes the old owner's keys and the unscoped keys of
earlier builds.
touch(), which runs every 30 s, adopts closed tabs' saved writes once
this tab has read: a tab with nothing to sync never re-reads, so they
waited until a tab switch or reload.
UserDataStorage gains an optional ready(); the server storage resolves
it after its first read and rejects while that fails. A PWA backup
export awaits it, so a fresh browser whose /user-state read is slow or
failed cannot export empty favorites, history and positions.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
When touch() finds that the previous page load no longer looks live, this
page may already have read and queued newer edits. Its saved writes and
early edits are now adopted like a closed tab's (their steps ahead of this
page's newer ones, queued at once) instead of restored as if this page
had just started, which replaced newer progress with older and parked
early edits that were never sent after the first read. Cache forgetting
moves into UserDataCache.forget().
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
ServerUserDataStorage remembers the map getItem handed out. When the
cache changed since (another tab saved, a re-read), a write applies only
the entries the caller changed to the current cache, so a map read
before another tab's save no longer reads as deleting that save. The
cache moves into UserDataCache.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
