HeaderBar (42px, sidebar cycle, back/forward, centered search replica,
offline badge + flyout, app menu), three-state Sidebar (open 240 / mini
64 / closed 0, 160ms animation, nav rows with exact msgids), NowPlaying
bar SMALL (3px three-color seekbar, art+title+time left, transport
center, quality/volume/queue-toggle right, exact empty state), Queue
panel (300px animated column, Queue/History tabs, exact empty states).
Nav history stack + NowPlayingModel with empty-state defaults behind
new bridge properties/invokables (transport log-and-noop until
playback lands). Icons as pre-baked tinted SVG variants (ColorOverlay
is broken on the software path); Inter fonts bundled; full dark theme
tokens ported from the Slint foundation files.
km