Add cover thumbnail and chapter list drawer to audio mini-bar

- Store cover and chapters array in audioStore (populated by AudioPlayer on startPlayback)
- Page server returns full chapters list on normal path; empty array on preview
- Mini-bar: replace arrow link with book cover thumbnail (fallback book icon)
- Mini-bar track info area is now a button that toggles a chapter list drawer
- Chapter drawer slides up above the mini-bar, lists all chapters with current one highlighted

ui/src/lib/audio.svelte.ts

@@ -44,6 +44,12 @@ class AudioStore {
 	voice = $state('af_bella');
 	speed = $state(1.0);
 
+	/** Cover image URL for the currently loaded book. */
+	cover = $state('');
+
+	/** Full chapter list for the currently loaded book (number + title). */
+	chapters = $state<{ number: number; title: string }[]>([]);
+
 	// ── Loading/generation state ────────────────────────────────────────────
 	status = $state<AudioStatus>('idle');
 	audioUrl = $state('');

ui/src/lib/components/AudioPlayer.svelte

@@ -59,6 +59,8 @@
 		cover?: string;
 		/** Next chapter number, or null/undefined if this is the last chapter. */
 		nextChapter?: number | null;
+		/** Full chapter list for the book (number + title). Written into the store. */
+		chapters?: { number: number; title: string }[];
 		/** List of available voices from the Kokoro API. */
 		voices?: string[];
 	}
@@ -70,6 +72,7 @@
 		bookTitle = '',
 		cover = '',
 		nextChapter = null,
+		chapters = [],
 		voices = []
 	}: Props = $props();
 
@@ -405,6 +408,8 @@
 		audioStore.chapter = chapter;
 		audioStore.chapterTitle = chapterTitle;
 		audioStore.bookTitle = bookTitle;
+		audioStore.cover = cover;
+		audioStore.chapters = chapters;
 
 		// Update OS media session (lock screen / notification center).
 		setMediaSession();

ui/src/routes/+layout.svelte

@@ -11,6 +11,9 @@
 	// Mobile nav drawer state
 	let menuOpen = $state(false);
 
+	// Chapter list drawer state for the mini-player
+	let chapterDrawerOpen = $state(false);
+
 	// The single <audio> element that persists across navigations.
 	// AudioPlayer components in chapter pages control it via audioStore.
 	let audioEl = $state<HTMLAudioElement | null>(null);
@@ -375,6 +378,45 @@
 {#if audioStore.active}
 	<div class="fixed bottom-0 left-0 right-0 z-50 bg-zinc-900 border-t border-zinc-700 shadow-2xl">
 
+		<!-- Chapter list drawer (slides up above the mini-bar) -->
+		{#if chapterDrawerOpen && audioStore.chapters.length > 0}
+			<div class="border-b border-zinc-700 bg-zinc-900 max-h-64 overflow-y-auto">
+				<div class="max-w-6xl mx-auto px-4">
+					<div class="flex items-center justify-between py-2 border-b border-zinc-800 sticky top-0 bg-zinc-900">
+						<span class="text-xs font-semibold text-zinc-400 uppercase tracking-wider">Chapters</span>
+						<button
+							onclick={() => (chapterDrawerOpen = false)}
+							class="text-zinc-600 hover:text-zinc-300 transition-colors p-1"
+							aria-label="Close chapter list"
+						>
+							<svg class="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+								<path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 9l-7 7-7-7"/>
+							</svg>
+						</button>
+					</div>
+					{#each audioStore.chapters as ch (ch.number)}
+						<a
+							href="/books/{audioStore.slug}/chapters/{ch.number}"
+							onclick={() => (chapterDrawerOpen = false)}
+							class="flex items-center gap-2 py-2 text-xs transition-colors hover:text-zinc-100 {ch.number === audioStore.chapter
+								? 'text-amber-400 font-semibold'
+								: 'text-zinc-400'}"
+						>
+							<span class="tabular-nums text-zinc-600 w-8 shrink-0 text-right">
+								{ch.number}
+							</span>
+							<span class="truncate">{ch.title || `Chapter ${ch.number}`}</span>
+							{#if ch.number === audioStore.chapter}
+								<svg class="w-3 h-3 shrink-0 text-amber-400" fill="currentColor" viewBox="0 0 24 24">
+									<path d="M8 5v14l11-7z"/>
+								</svg>
+							{/if}
+						</a>
+					{/each}
+				</div>
+			</div>
+		{/if}
+
 		<!-- Generation progress bar (sits at very top of the bar) -->
 		{#if audioStore.status === 'generating' || audioStore.status === 'loading'}
 			<div class="h-0.5 bg-zinc-800">
@@ -400,8 +442,13 @@
 
 		<div class="max-w-6xl mx-auto px-4 py-2 flex items-center gap-3">
 
-			<!-- Track info -->
-			<div class="flex-1 min-w-0">
+		<!-- Track info (click to open chapter list drawer) -->
+			<button
+				class="flex-1 min-w-0 text-left rounded px-1 -ml-1 hover:bg-zinc-800 transition-colors"
+				onclick={() => { if (audioStore.chapters.length > 0) chapterDrawerOpen = !chapterDrawerOpen; }}
+				aria-label={audioStore.chapters.length > 0 ? 'Toggle chapter list' : undefined}
+				title={audioStore.chapters.length > 0 ? 'Chapter list' : undefined}
+			>
 				{#if audioStore.chapterTitle}
 					<p class="text-xs text-zinc-100 truncate leading-tight">{audioStore.chapterTitle}</p>
 				{/if}
@@ -419,7 +466,7 @@
 				{:else if audioStore.status === 'loading'}
 					<p class="text-xs text-zinc-500 leading-tight">Loading…</p>
 				{/if}
-			</div>
+			</button>
 
 			{#if audioStore.status === 'ready'}
 				<!-- Skip back 15s -->
@@ -510,17 +557,28 @@
 				</svg>
 			{/if}
 
-			<!-- Go to chapter link (only when we know which chapter is playing) -->
+			<!-- Cover thumbnail / go-to-chapter link -->
 			{#if audioStore.slug && audioStore.chapter > 0}
 				<a
 					href="/books/{audioStore.slug}/chapters/{audioStore.chapter}"
-					class="text-zinc-400 hover:text-zinc-100 transition-colors p-1.5 rounded flex-shrink-0"
+					class="shrink-0 rounded overflow-hidden hover:opacity-80 transition-opacity"
 					title="Go to chapter"
 					aria-label="Go to chapter"
 				>
-					<svg class="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-						<path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M13 7l5 5m0 0l-5 5m5-5H6"/>
-					</svg>
+					{#if audioStore.cover}
+						<img
+							src={audioStore.cover}
+							alt=""
+							class="w-8 h-11 object-cover rounded"
+						/>
+					{:else}
+						<!-- Fallback book icon -->
+						<div class="w-8 h-11 flex items-center justify-center bg-zinc-800 rounded border border-zinc-700">
+							<svg class="w-4 h-4 text-zinc-500" fill="currentColor" viewBox="0 0 24 24">
+								<path d="M18 2H6c-1.1 0-2 .9-2 2v16c0 1.1.9 2 2 2h12c1.1 0 2-.9 2-2V4c0-1.1-.9-2-2-2zm-2 14H8v-2h8v2zm0-4H8v-2h8v2zm0-4H8V6h8v2z"/>
+							</svg>
+						</div>
+					{/if}
 				</a>
 			{/if}
 

ui/src/routes/books/[slug]/chapters/[n]/+page.server.ts

@@ -77,6 +77,7 @@ export const load: PageServerLoad = async ({ params, url, locals }) => {
 			voices,
 			prev: null as number | null,
 			next: null as number | null,
+			chapters: [] as { number: number; title: string }[],
 			sessionId: locals.sessionId,
 			isPreview: true
 		};
@@ -129,6 +130,7 @@ export const load: PageServerLoad = async ({ params, url, locals }) => {
 		voices,
 		prev: prevChapter ? prevChapter.number : null,
 		next: nextChapter ? nextChapter.number : null,
+		chapters: chapters.map((c) => ({ number: c.number, title: c.title })),
 		sessionId: locals.sessionId,
 		isPreview: false
 	};

ui/src/routes/books/[slug]/chapters/[n]/+page.svelte

@@ -103,6 +103,7 @@
 	bookTitle={data.book.title}
 	cover={data.book.cover}
 	nextChapter={data.next}
+	chapters={data.chapters}
 	voices={data.voices}
 />
 {:else}