Replaces the M5b-era single-entry <TrackMenu> with a 9-entry kebab
menu in 4 groups (queue / collection / navigation / lifecycle).
Reserves the "Add to playlist..." slot for #352. Lands a new
admin-only DELETE /api/admin/tracks/{id} for "Remove from library"
with cascade album -> artist tidy-up and Lidarr-aware deletion for
managed tracks.
Track metadata editing split out as #373 — different feature concern
(crosses into Lidarr's territory + scanner reconciliation).
bvandeusen
136a475133