Videos within a playlist can now be dragged to reorder (desktop), on top of the
↑/↓ buttons kept for touch/accessibility. HTML5 DnD delegated on the list:
dragstart records the row's playlist + index, dragover highlights the drop
target (accent inset bar) and allows the drop, drop reorders via
reorderPlaylistItems and publishes optimistically. Drag is scoped to a single
playlist (can't cross playlists); dragging row dims to 0.5; grab/grabbing cursor.
Lint + build clean; profile-modal-controller tests 26/26.
Co-Authored-By: Claude Opus 4.8 <[email protected]>