Revert chrome-bg: sidebar/queue should just be the tinted background

Per feedback, the solid color-mix bar was wrong — sidebar, queue and
the mobile header should stay on the plain --mf-bg (the same subtly
hue-shifting black used everywhere else), exactly like light mode
already does, not a separately-boosted colored panel. Drop --mf-chrome-bg/
--color-chrome and switch those three back to bg-bg.

The general dark-mode richness bump (tc(), --mf-bg/--mf-elevated/etc.)
and the glass-bar background-color fix from the previous commit stay;
only the separate chrome treatment is reverted.

web-player/src/lib/components/player/Queue.svelte

@@ -18,7 +18,7 @@
 {#if queuePanel.open}
 	<aside
 		transition:fly={{ x: 24, duration: 220, easing: cubicOut }}
-		class="hidden shrink-0 flex-col border-l border-hairline bg-chrome px-4 pt-5 sm:flex"
+		class="hidden shrink-0 flex-col border-l border-hairline bg-bg px-4 pt-5 sm:flex"
 		style="width:var(--mf-queue-w); padding-bottom:calc(var(--mf-player-h) + 2rem)"
 	>
 		<div class="mb-5 flex items-center justify-between">