Add exam attempt history summary DTO

src/main/java/com/example/questionbank/web/rest/dto/ExamAttemptSummary.java

@@ -0,0 +1,14 @@
+package com.example.questionbank.web.rest.dto;
+
+import com.example.questionbank.domain.enumeration.AttemptStatus;
+import java.time.Instant;
+
+public record ExamAttemptSummary(
+    Long attemptId,
+    Long subjectId,
+    String subjectName,
+    Instant startedAt,
+    Instant submittedAt,
+    AttemptStatus status,
+    Integer score
+) {}