The Large dock was a bare cover overlay: the sidebar knew nothing about it,
so the playlist rows kept running to the sidebar's bottom edge and sat
underneath the album art. Sidebar.slint reserves the in-sidebar portion of
the dock; the port had dropped that.
Reserve it the same way, from a single source of truth. QbzShell gains
largeDockHeight (shell_bridge.rs owns the arithmetic: 9 top + band + gap +
208 art + 4 bottom), the sidebar subtracts largeDockHeight - npbLargeHeight
from the playlist list, and AppShell pins the overlay at height -
largeDockHeight. The 112px bar height becomes a theme token so the shell and
the reservation cannot drift apart.
The band the cover was missing needs the FFT tap, so wire it: the runtime is
built with_visualizer, viz_qt.rs runs the frontend-agnostic producer from
qbz-audio and drains it at 30fps into a new QbzViz domain bridge as typed
QList<f32>. Bars (28 mirrored columns over the 14 active bins), Waveform (48
downsampled L columns) and Energy (5 bands) render as Slint does, the cover's
eye button toggles the band, clicking it cycles the mode, and both persist to
ui_prefs.
Cost is zero when unused: the tap starts disabled, the eye toggle gates
capture, the drain thread parks while off, and the transport is mirrored so a
paused player parks the producer instead of re-analyzing a stale buffer. The
QML binds bar HEIGHTS against static-model Repeaters — the lists are replaced
per frame, so a model binding would rebuild every delegate 30 times a second.
Adds the eye/eye-off icon pair to the seven baked tint variants.
18/18 tests; offscreen smoke clean (0 QML errors, home published).
cc