feat(cards): multiple-choice Card-Type mit dynamischen Distractors
- CardTypeSchema: 'multiple-choice' (Felder: front + answer, distractor_pool optional)
- subIndexCount: 'multiple-choice' → 1
- GET /api/v1/decks/:deckId/distractors: N zufällige Feldwerte anderer Karten
im Deck; field-Allowlist (front/back/answer/question); RANDOM() ORDER; Fallback
auf distractor_pool wenn Deck < 4 Karten
- fetchDistractors(): Frontend-Client-Funktion
- MultipleChoiceView.svelte: lädt Distractors on mount, shuffelt 4 Optionen,
zeigt Sofort-Feedback (correct/wrong/neutral), Keyboard 1–4 + Space;
auto-grade correct→good, wrong→again
- Study-Page: isMultipleChoice + multipleChoiceData derived, Action-Bar
ausgeblendet, onKey delegiert
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>