Quiz: draw the question figure under the prompt (Question.figure)

src/api/types.ts

@@ -149,6 +149,8 @@ export interface Question {
   type: string;
   prompt: string;
   options: QuestionOption[];
+  /** شکلِ سوال (همان قالبِ شکلِ درس‌ها)؛ null یعنی شکل ندارد. */
+  figure?: DiagramSpec | null;
 }
 
 export interface NodeQuizQuestion extends Question {

src/screens/QuizScreen.tsx

@@ -16,6 +16,7 @@ import { ErrorState, InlineError, LoadingState, PrimaryButton, SecondaryButton,
 import { friendlyError } from '@/lib/errors';
 import { toFa } from '@/lib/format';
 import { MathText } from '@/lib/MathText';
+import { Diagram } from '@/diagram';
 import { sounds } from '@/lib/sound';
 import { useGateHold } from '@/lib/useAsync';
 import { StreakCelebration, StreakFlame } from '@/components/StreakFlame';
@@ -348,6 +349,7 @@ export function QuizScreen({ lessonId, nodeId }: { lessonId?: number; nodeId?: s
             </button>
           </div>
           <h2 className="whitespace-pre-line text-base font-bold leading-8 text-ink"><MathText text={question.prompt} /></h2>
+          {question.figure ? <div className="mt-3"><Diagram spec={question.figure} /></div> : null}
         </div>
 
         <div className={shortOptions ? 'grid grid-cols-2 gap-2.5' : 'flex flex-col gap-2.5'}>