[xingyu.guo] fix: 统一Id为Num，在自己的业务领域中使用id，在非本身业务范畴的领域使用num

src/main/java/com/guo/learningprogresstracker/entity/StudySessionsEntity.java

@@ -21,14 +21,17 @@ import java.time.LocalDateTime;
 @Data
 public class StudySessionsEntity extends BaseEntity implements Serializable {
 
-    @TableId(value = "session_id", type = IdType.AUTO)
-    private Integer sessionId;
+    @TableId(type = IdType.AUTO)
+    private Integer id;
+
+    @TableField(value = "session_num")
+    private String sessionNum;
 
     /**
      * 
      */
-    @TableField(value = "task_id")
-    private Integer taskId;
+    @TableField(value = "task_num")
+    private String taskNum;
 
     /**
      * 学习开始时间