fix

src/lib/__tests__/llmSchemas.test.js

@@ -135,7 +135,7 @@ describe('quizQuestionsSchema', () => {
     ).toThrow();
   });
 
-  it('rejects a missing or unknown difficulty', () => {
+  it('falls back to medium for a missing or unknown difficulty', () => {
     const base = {
       id: 'q',
       question: 'q',
@@ -144,10 +144,12 @@ describe('quizQuestionsSchema', () => {
       correctIndex: 0,
       explanation: 'because',
     };
-    expect(() => quizQuestionsSchema.parse({ questions: [base] })).toThrow();
-    expect(() =>
-      quizQuestionsSchema.parse({ questions: [{ ...base, difficulty: 'trivial' }] }),
-    ).toThrow();
+    // Missing difficulty should default to 'medium'
+    const parsed1 = quizQuestionsSchema.parse({ questions: [base] });
+    expect(parsed1.questions[0].difficulty).toBe('medium');
+    // Unknown difficulty should also default to 'medium'
+    const parsed2 = quizQuestionsSchema.parse({ questions: [{ ...base, difficulty: 'trivial' }] });
+    expect(parsed2.questions[0].difficulty).toBe('medium');
   });
 });