[codex] Add compact play queue popover

[constansino]

Summary

• add a compact play queue popover in the bottom play bar
• show queued Play Later songs plus nearby songs from the current playback list
• add one-click Play Later actions to online search results, including the default hidden-action-buttons layout

Details

The queue popover reuses the existing tempPlayList / Play Later state and only renders the Play Later list plus a small slice around the current song from the active playback list. This keeps the UI useful for knowing the current/previous/next context without rendering large source lists.

For online search results, the existing row action buttons now support Play Later, and the layout with list action buttons disabled gets a small hover/focus Play Later shortcut on each visible virtualized row.

Validation

• npm run lint
• npm run build:renderer
• verified in the Electron dev window that the play queue button appears in the play bar
• verified the queue popover shows current list context and Play Later count
• verified clicking a search result Play Later shortcut increments the queue badge

[constansino]