feat: end-to-end choice question support in assessment pipeline

- Data pathway: flow options through questions, answerKey in graph state
- Interviewer: format MULTIPLE_CHOICE with A/B/C/D options
- Grader: instant choice scoring (zero LLM), compare correctAnswer
- AssessmentView: render choice buttons vs textarea based on questionType
- Security: sanitizeStateForClient strips correctAnswer/judgment/answerKey
- Bank detection: check PUBLISHED items (not PUBLISHED bank status)
- Batch UI: select all / batch approve / batch reject on detail view

server/src/assessment/graph/nodes/generator.node.ts

@@ -230,6 +230,7 @@ ${existingQuestionsText ? `- Repeating previous questions: ${existingQuestionsTe
         return {
           id: (existingQuestions.length + 1).toString(),
           questionText: q.question_text,
+          questionType: 'SHORT_ANSWER',
           keyPoints: q.key_points,
           difficulty: q.difficulty,
           basis: q.basis,

server/src/assessment/graph/nodes/grader.node.ts

@@ -67,6 +67,31 @@ export const graderNode = async (
     return { currentQuestionIndex: currentQuestionIndex + 1 };
   }
 
+  const isChoice = currentQuestion.questionType === 'MULTIPLE_CHOICE';
+  const answerKey = (state.questionAnswerKey as any)?.[currentQuestion.id];
+
+  if (isChoice || answerKey?.correctAnswer) {
+    const expectedAnswer = answerKey?.correctAnswer || currentQuestion.correctAnswer;
+    const userAnswer = (lastUserMessage.content as string).trim();
+    const isCorrect = userAnswer.toUpperCase() === expectedAnswer?.toUpperCase();
+
+    console.log('[GraderNode] Choice grading:', { userAnswer, expectedAnswer, isCorrect });
+
+    const feedback = isCorrect ? '✅ 正确' : `❌ 错误，正确答案是 ${expectedAnswer}`;
+    const feedbackMessage = new AIMessage(
+      { content: `Score: ${isCorrect ? 10 : 0}\nFeedback: ${feedback}` } as any,
+    );
+
+    return {
+      messages: [feedbackMessage],
+      feedbackHistory: [feedbackMessage],
+      scores: { [currentQuestion.id || currentQuestionIndex.toString()]: isCorrect ? 10 : 0 },
+      shouldFollowUp: false,
+      followUpCount: 0,
+      currentQuestionIndex: currentQuestionIndex + 1,
+    };
+  }
+
   const systemPromptZh = `你是一位专业的考官。
 请根据以下问题和关键点对用户的回答进行评分。
 

server/src/assessment/graph/nodes/interviewer.node.ts

@@ -33,8 +33,6 @@ export const interviewerNode = async (
 
   const currentQuestion = questions[currentQuestionIndex];
 
-  // If it's a follow-up, we add a prefix to the label later.
-  // If we've run out of questions and no follow-up requested, we shouldn't be here, but let's be safe.
   if (currentQuestionIndex >= questions.length) {
     return { shouldFollowUp: false };
   }
@@ -49,12 +47,10 @@ export const interviewerNode = async (
     state.feedbackHistory &&
     state.feedbackHistory.length > 0
   ) {
-    // Construct a follow-up prompt based on last feedback
     const lastFeedbackMsg =
       state.feedbackHistory[state.feedbackHistory.length - 1];
     const feedbackText = lastFeedbackMsg.content.toString();
 
-    // Extract the "Feedback: ..." part if possible, otherwise use whole text
     const feedbackMatch = feedbackText.match(
       /(?:Feedback|反馈|フィードバック): ([\s\S]*)/i,
     );
@@ -74,8 +70,22 @@ export const interviewerNode = async (
         : 'Based on the feedback above, please provide more specific details:';
 
     prompt = `${followUpLabel}\n\n${specificFeedback}\n\n${followUpInstruction}`;
+  } else if (currentQuestion.questionType === 'MULTIPLE_CHOICE' && currentQuestion.options?.length > 0) {
+    const label = isZh
+      ? `问题 ${currentQuestionIndex + 1}`
+      : isJa
+        ? `質問 ${currentQuestionIndex + 1}`
+        : `Question ${currentQuestionIndex + 1}`;
+
+    const optionsText = currentQuestion.options.join('\n');
+    const instruction = isZh
+      ? '请选择一个选项（输入字母 A/B/C/D）'
+      : isJa
+        ? '選択肢から1つ選んでください（A/B/C/Dを入力）'
+        : 'Please select one option (enter A, B, C, or D)';
+
+    prompt = `${label}: ${currentQuestion.questionText}\n\n${optionsText}\n\n${instruction}`;
   } else {
-    // Standard question presentation
     const label = isZh
       ? `问题 ${currentQuestionIndex + 1}`
       : isJa

server/src/assessment/graph/state.ts

@@ -119,6 +119,15 @@ export const EvaluationAnnotation = Annotation.Root({
   keywords: Annotation<string[] | undefined>({
     reducer: (prev, next) => next ?? prev,
   }),
+
+  /**
+   * Answer key for bank questions: id → { correctAnswer, judgment, followupHints }.
+   * Used by grader for instant choice scoring and open-question anchoring.
+   * NOT sent to frontend.
+   */
+  questionAnswerKey: Annotation<Record<string, any> | undefined>({
+    reducer: (prev, next) => next ?? prev,
+  }),
 });
 
 export type EvaluationState = typeof EvaluationAnnotation.State;