fix(quiz): skip legacy questions with missing type instead of throwing

Legacy Runtime test data may contain questions without an explicit
type field. For missing type -> skip with warning (consistent with
missing stem/answer handling). For non-empty illegal type -> throw
BadRequestException (fail-closed).

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

src/modules/ai-runtime/internal/runtime-internal.service.spec.ts

@@ -581,7 +581,7 @@ describe('RuntimeInternalService', () => {
     });
 
     it('persists quiz_generation output (creates quiz + questions)', async () => {
-      const qDto = { ...dto, validatedOutput: { questions: [{ stem: 'Q1?', answer: 'A1' }] } };
+      const qDto = { ...dto, validatedOutput: { questions: [{ type: 'choice', stem: 'Q1?', answer: 'A1' }] } };
       const qJob = { ...job, jobType: 'quiz_generation' as const, targetType: 'knowledge_base' as const, targetId: 'kb1' };
       mockAiRuntimeJob.findUnique.mockResolvedValue(qJob);
       mockAiRuntimeResult.findFirst.mockResolvedValue(null);
@@ -902,7 +902,7 @@ describe('RuntimeInternalService', () => {
 
       await service.submitResult('j1', {
         runtimeInstanceId: 'rt-1', schemaVersion: 'ov1', status: 'succeeded',
-        validatedOutput: { questions: [{ stem: 'Valid', answer: 'A' }, { stem: '', answer: '' }] },
+        validatedOutput: { questions: [{ type: 'choice', stem: 'Valid', answer: 'A' }, { stem: '', answer: '' }] },
         attemptNo: 1, outputHash: 'h1',
       });
 
@@ -914,7 +914,7 @@ describe('RuntimeInternalService', () => {
 
       await service.submitResult('j1', {
         runtimeInstanceId: 'rt-1', schemaVersion: 'ov1', status: 'succeeded',
-        validatedOutput: { questions: [{ stem: '', answer: '' }] },
+        validatedOutput: { questions: [{ type: 'choice', stem: '', answer: '' }] },
         attemptNo: 1, outputHash: 'h2',
       });
 
@@ -932,8 +932,8 @@ describe('RuntimeInternalService', () => {
         runtimeInstanceId: 'rt-1', schemaVersion: 'ov1', status: 'succeeded',
         validatedOutput: {
           questions: [
-            { stem: 'Duplicate?', answer: 'A' },
+            { type: 'choice', stem: 'Duplicate?', answer: 'A' },
-            { stem: 'Unique?', answer: 'B' },
+            { type: 'choice', stem: 'Unique?', answer: 'B' },
           ],
         },
         attemptNo: 1, outputHash: 'h3',
@@ -951,7 +951,7 @@ describe('RuntimeInternalService', () => {
 
       await service.submitResult('j1', {
         runtimeInstanceId: 'rt-1', schemaVersion: 'ov1', status: 'succeeded',
-        validatedOutput: { questions: [{ stem: 'Q?', answer: 'A' }] },
+        validatedOutput: { questions: [{ type: 'choice', stem: 'Q?', answer: 'A' }] },
         attemptNo: 1, outputHash: 'h4',
       });
 

src/modules/ai-runtime/internal/runtime-internal.service.ts

@@ -481,11 +481,19 @@ export class RuntimeInternalService {
         continue;
       }
 
+      // M-QUIZ-01-CLEANUP-01: 缺失 type → 跳过 + 警告（兼容旧数据）；非法非空 type → 拒绝
+      if (!q.type) {
+        this.logger.warn(`convertQuizCandidates: skipping question with missing type for job=${job.id}`);
+        continue;
+      }
+      if (!isValidQuestionType(q.type)) {
+        throw new BadRequestException(`Invalid question type: ${q.type}`);
+      }
+
       await this.prisma.quizQuestion.create({
         data: {
           quizId: quiz.id,
-          // M-QUIZ-01-04: fail-closed — 非法 type 记录错误并拒绝
+          type: q.type,
-          type: isValidQuestionType(q.type) ? q.type! : (() => { throw new BadRequestException(`Invalid question type: ${q.type}`); })(),
           stem,
           options: q.options ?? undefined,
           answer: q.answer ?? q.correctAnswer,