Rewrites ABSPlaylistStore methods to read/write user_personal_collections
(collection_type='playlist') and user_personal_collection_items
(sub_item_id replaces episode_id). DeletePlaylist runs in a transaction
since the items table has no FK cascade. Drops the coverArg helper —
the canonical schema has no cover_item column, so CoverItem is always
emitted as zero value per spec §6 deferral.
In-memory abs.Playlist / abs.PlaylistItem struct shape unchanged;
playlistToABS() emitter preserves the wire-shape contract.
Note: user_personal_collection_items PRIMARY KEY is (user_id,
collection_id, media_item_id) — sub_item_id is NOT part of it. The
old abs_playlist_items PK included episode_id, so a playlist that
referenced multiple episodes of the same library item had distinct
rows. Under the canonical PK the second insert silently collides;
prod baseline has zero playlist items so no live data is affected.
Multi-episode-of-same-book inside one playlist would require a schema
change (extend PK / add unique index) and is out of scope here.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
