- Event delegation handlers were attached in firstUpdated(), but the
virtualizer is conditionally rendered (hidden when tracks empty/loading)
- On first render, tracks are [] so virtualizer doesn't exist, and
firstUpdated() never fires again — delegation was never attached
- Move delegation to a guarded helper called from both firstUpdated()
and updated(), so it attaches as soon as the virtualizer appears
- Fixes click, multi-select, context menu, double-click, and drag in
both track-list and queue-panel components
yonlu
f05d2bb603