feat(cards): audio-front Card-Type

- CardTypeSchema: 'audio-front' als vollwertiger Type (fields: audio_ref + back + front?)
- subIndexCount: 'audio-front' → 1
- AudioFrontView.svelte: custom Play/Pause-Button, audio via /api/v1/media/:id,
  optionaler Hint-Text; Antwort-Markdown läuft über bestehenden answerHtml-Pfad
- Study-Page: isAudioFront + audioFrontData derived, AudioFrontView eingebunden

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/src/lib/components/AudioFrontView.svelte

@@ -0,0 +1,98 @@
+<script lang="ts">
+	import { API_BASE } from '$lib/api/client.ts';
+
+	let {
+		audioRef,
+		frontText,
+	}: {
+		audioRef: string;
+		frontText?: string;
+	} = $props();
+
+	let audioEl = $state<HTMLAudioElement | null>(null);
+	let playing = $state(false);
+
+	const audioUrl = $derived(`${API_BASE}/api/v1/media/${audioRef}`);
+
+	function toggle() {
+		if (!audioEl) return;
+		if (playing) {
+			audioEl.pause();
+		} else {
+			audioEl.play();
+		}
+	}
+</script>
+
+<div class="audio-front">
+	<!-- svelte-ignore a11y_media_has_caption -->
+	<audio
+		bind:this={audioEl}
+		src={audioUrl}
+		preload="metadata"
+		onplay={() => (playing = true)}
+		onpause={() => (playing = false)}
+		onended={() => (playing = false)}
+	></audio>
+
+	<button class="play-btn" onclick={toggle} aria-label={playing ? 'Pause' : 'Abspielen'}>
+		{#if playing}
+			<svg viewBox="0 0 24 24" fill="currentColor" width="28" height="28" aria-hidden="true">
+				<rect x="6" y="4" width="4" height="16" rx="1" />
+				<rect x="14" y="4" width="4" height="16" rx="1" />
+			</svg>
+		{:else}
+			<svg viewBox="0 0 24 24" fill="currentColor" width="28" height="28" aria-hidden="true">
+				<polygon points="5,3 20,12 5,21" />
+			</svg>
+		{/if}
+	</button>
+
+	{#if frontText}
+		<p class="hint">{frontText}</p>
+	{/if}
+</div>
+
+<style>
+	.audio-front {
+		display: flex;
+		flex-direction: column;
+		align-items: center;
+		justify-content: center;
+		gap: 1.25rem;
+		padding: 1.5rem 0;
+		width: 100%;
+	}
+
+	.play-btn {
+		width: 5rem;
+		height: 5rem;
+		border-radius: 50%;
+		background: hsl(var(--color-primary));
+		color: hsl(var(--color-primary-foreground));
+		border: none;
+		cursor: pointer;
+		display: flex;
+		align-items: center;
+		justify-content: center;
+		box-shadow: 0 4px 16px hsl(var(--color-primary) / 0.35);
+		transition: transform 0.15s ease, box-shadow 0.15s ease;
+	}
+
+	.play-btn:hover {
+		transform: scale(1.06);
+		box-shadow: 0 6px 20px hsl(var(--color-primary) / 0.45);
+	}
+
+	.play-btn:active {
+		transform: scale(0.96);
+	}
+
+	.hint {
+		margin: 0;
+		font-size: 1rem;
+		color: hsl(var(--color-muted-foreground));
+		text-align: center;
+		line-height: 1.5;
+	}
+</style>

apps/web/src/routes/study/[deckId]/+page.svelte

@@ -16,6 +16,7 @@
 	import { toasts } from '$lib/stores/toasts.svelte.ts';
 	import { t } from '$lib/i18n/index.svelte.ts';
 	import ImageOcclusionView from '$lib/components/ImageOcclusionView.svelte';
+	import AudioFrontView from '$lib/components/AudioFrontView.svelte';
 	import CardSurface from '$lib/components/CardSurface.svelte';
 
 	const deckId = $derived(page.params.deckId ?? '');
@@ -93,6 +94,17 @@
 		};
 	});
 
+	const isAudioFront = $derived(current?.card?.type === 'audio-front');
+	const audioFrontData = $derived.by(() => {
+		const c = current;
+		if (!c?.card || c.card.type !== 'audio-front') return null;
+		const fields = c.card.fields as Record<string, string>;
+		return {
+			audioRef: fields.audio_ref ?? '',
+			frontText: fields.front || undefined,
+		};
+	});
+
 	onMount(async () => {
 		if (!devUser.id) {
 			goto('/');
@@ -216,8 +228,15 @@
 							activeMaskId={imageOcclusionData.activeMaskId}
 							{revealed}
 						/>
+					{:else}
+						{#if isAudioFront && audioFrontData}
+							<AudioFrontView
+								audioRef={audioFrontData.audioRef}
+								frontText={audioFrontData.frontText}
+							/>
 						{:else}
 							<div class="prose">{@html promptHtml}</div>
+						{/if}
 						{#if revealed}
 							<hr class="divider" />
 							<div class="prose answer">{@html answerHtml}</div>

packages/cards-domain/src/fsrs.ts

@@ -147,7 +147,7 @@ export function subIndexCount(type: string): number {
 			throw new Error(
 				'subIndexCount("image-occlusion") not supported — use maskRegionCount(fields.mask_regions) from @cards/domain'
 			);
-		case 'audio':
+		case 'audio-front':
 			return 1;
 		case 'multiple-choice':
 			return 1;

packages/cards-domain/src/schemas/card.ts

@@ -10,6 +10,7 @@ export const CardTypeSchema = z.enum([
 	'basic-reverse',
 	'cloze',
 	'image-occlusion',
+	'audio-front',
 ]);
 export type CardType = z.infer<typeof CardTypeSchema>;
 
@@ -20,7 +21,7 @@ export const CardTypeFutureSchema = z.enum([
 	'cloze',
 	'type-in',
 	'image-occlusion',
-	'audio',
+	'audio-front',
 	'multiple-choice',
 ]);
 
@@ -46,7 +47,7 @@ export function validateFieldsForType(
 		cloze: ['text'],
 		'type-in': ['question', 'expected'],
 		'image-occlusion': ['image_ref', 'mask_regions'],
-		audio: ['audio_ref'],
+		'audio-front': ['audio_ref', 'back'],
 		'multiple-choice': ['question', 'options', 'correct_index'],
 	};
 	const need = required[type] ?? [];