fix(cast): mirror Settings tier names in the device cap, drop the 48kHz copy (#638)

The per-renderer cap dropdown now uses the plain Settings product names (Hi-Res / CD Quality / MP3, looked up by key so they can't drift) instead of the misleading verbose 'CD - 16-bit / 44.1 kHz' form - a CD-tier track can be 48 kHz; the tier is a format_id, not a fixed rate. Removed the '...no 48 kHz option' caption. quality_label_from_track detail is now bit-depth-first to match every other badge.

cc

crates/qbz-ui/ui/shell/CastPicker.slint

@@ -280,15 +280,6 @@ export component CastPicker inherits Rectangle {
                     }
                 }
 
-                // The literal answer to #638: Qobuz sells four discrete
-                // tiers — there is no 48 kHz tier to offer.
-                if CastState.connected && CastState.device-cap-available: Text {
-                    text: @tr("Qobuz only offers these tiers — there is no 48 kHz option. The step below Hi-Res is CD 44.1 kHz.");
-                    color: Theme.text-muted;
-                    font-size: Typography.legal;
-                    wrap: word-wrap;
-                }
-
                 // ---- Tabs + device list (when not connected) ----
                 if !CastState.connected: HorizontalLayout {
                     spacing: 8px;