When a playlist has zero tracks, the detail screen previously showed
just the header with no indication of what to do next. Adds an inline
hint mirroring the web's copy: "No tracks yet. Add some via the
\"Add to playlist…\" entry on any track row."
Implementation: itemCount goes from tracks.length + 1 to
(tracks.isEmpty ? 2 : tracks.length + 1) and the builder emits the
hint at index 1 when tracks is empty. Header still renders at index 0.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
bvandeusen
dd848e76e8