Phase 8a: Cloze als MVP-Card-Type, Cluster-Counter

CardTypeSchema öffnet 'cloze' als drittes MVP-Set-Mitglied. Domain-Modul
@cards/domain/src/cloze.ts kapselt die Cluster-Logik (extractClusterIds,
subIndexCountForCloze, clusterIdForSubIndex, renderClozePrompt/Answer)
— Hint-Markup wird MVP-stumm gedroppt.

subIndexCount('cloze') wirft jetzt explizit, statt still auf 1 zu fallen,
weil die Cluster-Anzahl text-abhängig ist und ein silent-default falsch
dimensionierte Review-Tabellen produzieren würde. Card-POST-Handler holt
für Cloze die Anzahl aus subIndexCountForCloze und lehnt 422 ab, wenn
kein {{cN::…}}-Markup vorhanden ist.

12 neue Cloze-Tests, alle Domain- und API-Tests grün (41 + 46).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/api/src/routes/cards.ts

@@ -1,7 +1,13 @@
 import { and, eq } from 'drizzle-orm';
 import { Hono } from 'hono';
 
-import { CardCreateSchema, CardUpdateSchema, newReview, subIndexCount } from '@cards/domain';
+import {
+	CardCreateSchema,
+	CardUpdateSchema,
+	newReview,
+	subIndexCount,
+	subIndexCountForCloze,
+} from '@cards/domain';
 
 import { getDb, type CardsDb } from '../db/connection.ts';
 import { cards, decks, reviews } from '../db/schema/index.ts';
@@ -33,6 +39,22 @@ export function cardsRouter(deps: CardsDeps = {}): Hono<{ Variables: AuthVars }>
 		}
 		const userId = c.get('userId');
 
+		// Cloze: Sub-Index-Anzahl hängt vom Cluster-Markup im Text ab.
+		// Eine Cloze-Karte ohne `{{cN::…}}` ist sinnlos — vor dem Deck-Lookup
+		// ablehnen, damit Validation-Errors konsistent 422 statt 404 sind.
+		let count: number;
+		if (parsed.data.type === 'cloze') {
+			count = subIndexCountForCloze(parsed.data.fields.text ?? '');
+			if (count === 0) {
+				return c.json(
+					{ error: 'invalid_input', issues: ['cloze.text contains no {{cN::…}} clusters'] },
+					422
+				);
+			}
+		} else {
+			count = subIndexCount(parsed.data.type);
+		}
+
 		const [deck] = await dbOf()
 			.select({ id: decks.id, userId: decks.userId })
 			.from(decks)
@@ -43,7 +65,7 @@ export function cardsRouter(deps: CardsDeps = {}): Hono<{ Variables: AuthVars }>
 
 		const cardId = ulid();
 		const now = new Date();
-		const subIndices = Array.from({ length: subIndexCount(parsed.data.type) }, (_, i) => i);
+		const subIndices = Array.from({ length: count }, (_, i) => i);
 
 		const [cardRow] = await dbOf().transaction(async (tx) => {
 			const [card] = await tx

apps/api/tests/cards.test.ts

@@ -62,13 +62,59 @@ describe('cardsRouter — Input-Validation', () => {
 			headers: { 'X-User-Id': 'u-1', 'Content-Type': 'application/json' },
 			body: JSON.stringify({
 				deck_id: 'd-1',
-				type: 'cloze',
-				fields: { text: 'x' },
+				type: 'image-occlusion',
+				fields: { image_ref: 'x', mask_regions: 'y' },
 			}),
 		});
 		expect(res.status).toBe(422);
 	});
 
+	it('POST mit cloze-Card ohne text-Feld ist 422', async () => {
+		const { app } = buildApp();
+		const res = await app.request('/api/v1/cards', {
+			method: 'POST',
+			headers: { 'X-User-Id': 'u-1', 'Content-Type': 'application/json' },
+			body: JSON.stringify({
+				deck_id: 'd-1',
+				type: 'cloze',
+				fields: {},
+			}),
+		});
+		expect(res.status).toBe(422);
+	});
+
+	it('POST mit cloze-Card aber Text ohne Cluster ist 422', async () => {
+		const { app } = buildApp();
+		const res = await app.request('/api/v1/cards', {
+			method: 'POST',
+			headers: { 'X-User-Id': 'u-1', 'Content-Type': 'application/json' },
+			body: JSON.stringify({
+				deck_id: 'd-1',
+				type: 'cloze',
+				fields: { text: 'plain text without any {{cN::…}} markup' },
+			}),
+		});
+		expect(res.status).toBe(422);
+		const body = (await res.json()) as { error: string; issues: string[] };
+		expect(body.issues[0]).toMatch(/cloze\.text/);
+	});
+
+	it('POST mit gültiger cloze-Card erreicht Deck-Lookup (404 bei stub)', async () => {
+		const { app } = buildApp();
+		const res = await app.request('/api/v1/cards', {
+			method: 'POST',
+			headers: { 'X-User-Id': 'u-1', 'Content-Type': 'application/json' },
+			body: JSON.stringify({
+				deck_id: 'd-1',
+				type: 'cloze',
+				fields: { text: 'Capital of {{c1::France}} is {{c2::Paris}}.' },
+			}),
+		});
+		expect(res.status).toBe(404);
+		const body = (await res.json()) as { error: string };
+		expect(body.error).toBe('deck_not_found');
+	});
+
 	it('PATCH mit extra prop ist 422', async () => {
 		const { app } = buildApp();
 		const res = await app.request('/api/v1/cards/c-1', {