fix: linkedGroupIds null check in validateRequiredFields

null !== undefined was true, causing false validation failure on templates
without linked groups. Changed to != null check.

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

@@ -77,14 +77,13 @@ export const interviewerNode = async (
         ? `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）'
+      ? '请选择一个选项'
       : 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)';
+        ? '選択肢から1つ選んでください'
+        : 'Please select one option';
 
-    prompt = `${label}: ${currentQuestion.questionText}\n\n${optionsText}\n\n${instruction}`;
+    prompt = `${label}: ${currentQuestion.questionText}\n\n${instruction}`;
   } else {
     const label = isZh
       ? `问题 ${currentQuestionIndex + 1}`