The in-session undo/redo is lost when switching playlists, leaving no way to undo
local edits to a YouTube-linked list afterwards. Add a per-playlist 'Reset to YouTube'
action (shown when a linked playlist is dirty) that force-repulls that single playlist
from YouTube, replacing its items/order/name and clearing dirty — even though the bulk
read-sync skips dirty playlists. Backend: repull_playlist() + POST /api/playlists/
{id}/revert-youtube (read-scope gated). Confirm dialog (destructive). Trilingual.
Mirrors (source='youtube') were read-only; per the original two-way design they can
now be edited locally (add/remove/reorder/rename) and pushed back. The read-sync
skips a dirty mirror so it won't clobber unpushed edits; a successful push clears
dirty and lets the mirror refresh. _mark_dirty now covers any YouTube-linked list
(exported local or mirror), and rename marks dirty too. push/delete no longer reject
mirrors. Push reconciles the title as well (cheap playlists.list compare, then
playlists.update only if changed) so a local rename doesn't revert on the next pull.
Frontend: editable = not-built-in (was also excluding mirrors); rows/reorder enabled
for all owned lists; AddToPlaylist popover lists mirrors too (with a YT marker); the
origin chip now reads 'edits sync back'. Trilingual.
Local 'user' playlists (not Watch later, not YouTube mirrors) can now be pushed
to YouTube: create a new playlist on first push, else reconcile membership + order
so YouTube matches local (local wins). plan_push computes a dry-run estimate
(inserts/deletes/reorders + quota units + divergence) read from the live YouTube
state; push refuses if the estimate exceeds the remaining daily quota so a big
playlist can't strand half-pushed. Reorder uses an insertion-sort move count that
matches what executes. Edits to a linked playlist set dirty; a successful push
clears it. DELETE accepts on_youtube to also delete the playlist on YouTube. The
read-sync now skips YouTube playlists already owned by a local export, avoiding
duplicate read-only mirrors.
Mirror each user's own YouTube playlists into local source='youtube' playlists,
one-way (YT -> local). New client methods iter_my_playlists / iter_my_playlist_video_ids
(OAuth, so private playlists work); sync/playlists.py reconciles the mirror (matching YT
order) and ingests any playlist videos not in the shared catalog yet (with stub channels).
POST /api/playlists/sync-youtube for manual sync (read-scope gated, per-user quota) plus a
scheduler job (playlist_sync_minutes, default 6h) that syncs all read-scope users. YouTube's
Watch Later / History are not API-accessible and are never synced.
