The old per-video status='saved' becomes membership in a built-in, undeletable
'watch_later' playlist. Migration 0012 moves existing saved videos into each user's
Watch later list and demotes the states to 'new'. The feed/playlist serializers now
expose a 'saved' boolean (EXISTS in watch_later); the card bookmark toggles watch_later
via new /api/playlists/watch-later add/remove endpoints (create-on-demand) instead of
setting a status. Removed the 'saved' show-filter and status. Watch later shows a
localized name and hides rename/delete in the Playlists page and add-to-playlist popover.
The post-delete auto-select effect re-picked the just-deleted id from the still-stale
playlists cache, so its detail lingered. Select the next remaining playlist directly on
delete (or null), drop the deleted detail from the cache, and make the effect re-validate
the selection against the current list (clear when empty, reselect when the current id is
gone). Also fix the header title showing "Channel manager" on the Playlists page.
Add a promise-based ConfirmProvider + useConfirm() hook (built on the Modal shell,
liquid-glass styling, danger variant, Esc/backdrop = cancel, Enter = confirm) so
confirmations match the app instead of the native browser dialog. Wire it in at the
app root and replace both window.confirm call sites (playlist delete, channel
unsubscribe). Trilingual common.confirm/confirmTitle strings.
The detail pane rendered from react-query's cached data, so deleting the selected
playlist emptied the rail but left its stale contents on the right. Gate the detail
view on the current selection so it falls back to the empty state when nothing (or a
just-deleted playlist) is selected.
Add the Playlists page (left rail of playlists + detail with drag&drop reorder,
inline rename, one-step delete, remove item, Play all / row-click playback via the
existing PlayerModal) and an AddToPlaylist popover (portaled, multi-toggle +
inline new-playlist) wired into the VideoCard hover overlay and the PlayerModal.
New api client methods + Playlist types, a 'playlists' page route + account-menu
entry, and trilingual strings. Local only — YouTube sync comes in later phases.
