R1 先行批：question-center 后端（SB 2.7.18，23 单测全绿）+ 建表脚本 + 仓库说明

src/main/java/com/yunhai/question/entity/BaseEntity.java

@@ -0,0 +1,43 @@
+package com.yunhai.question.entity;
+
+import com.yunhai.question.common.QuestionAuditListener;
+import lombok.Getter;
+import lombok.Setter;
+
+import javax.persistence.Column;
+import javax.persistence.EntityListeners;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.MappedSuperclass;
+import java.io.Serializable;
+import java.time.LocalDateTime;
+
+/**
+ * 实体公共基类：自增主键 + 审计四件套（QuestionAuditListener 自动填充，flow-center 同款）。
+ * 多租户键 sch_id 不在基类——业务实体自带列。
+ */
+@MappedSuperclass
+@Getter
+@Setter
+@EntityListeners(QuestionAuditListener.class)
+public abstract class BaseEntity implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @Column(name = "create_by", updatable = false)
+    private String createBy;
+
+    @Column(name = "create_time", updatable = false)
+    private LocalDateTime createTime;
+
+    @Column(name = "update_by")
+    private String updateBy;
+
+    @Column(name = "update_time")
+    private LocalDateTime updateTime;
+}