feat: 办事大厅后端源码首次入库（事项/字典/表单/申报 + 流程回调）

src/main/java/com/yunhai/svchall/entity/ServiceFlowReg.java

@@ -0,0 +1,49 @@
+package com.yunhai.svchall.entity;
+
+import lombok.Getter;
+import lombok.Setter;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.Index;
+import javax.persistence.Table;
+import javax.persistence.UniqueConstraint;
+
+/**
+ * 流程回调注册（V2.0 Part B.2.6）：管理端在事项绑定 flow_guid 时经
+ * POST /oapi/flow/callback/reg 向流程中心注册并保存下发的 secret（回调签名密钥，
+ * 与应用级 appSecret 分离、粒度到"应用×流程"——流程中心概览 §4.8）。
+ * 同 flow_guid 多事项共享一条注册。
+ */
+@Getter
+@Setter
+@Entity
+@Table(name = "service_flow_reg",
+        uniqueConstraints = @UniqueConstraint(name = "uk_svc_flow_reg", columnNames = {"sch_id", "flow_guid"}),
+        indexes = @Index(name = "idx_svc_flow_reg_guid", columnList = "flow_guid"))
+public class ServiceFlowReg extends BaseEntity {
+
+    /** 租户键 */
+    @Column(name = "sch_id", nullable = false)
+    private Long schId;
+
+    /** 订阅的流程 */
+    @Column(name = "flow_guid", nullable = false, length = 32)
+    private String flowGuid;
+
+    /** 回调接收端点（= 本应用对外可达地址 + /callback/flow） */
+    @Column(name = "callback_url", nullable = false, length = 500)
+    private String callbackUrl;
+
+    /** 订阅事件逗号分隔（空=全部；flow.submitted/task.created/task.handled/completed/rejected/withdrawn） */
+    @Column(name = "event_types", length = 200)
+    private String eventTypes;
+
+    /** reg 接口下发的回调签名密钥（HmacSHA256；不回显给前端） */
+    @Column(name = "secret", nullable = false, length = 64)
+    private String secret;
+
+    /** 0 启用 / 1 停用 */
+    @Column(name = "status", nullable = false)
+    private Integer status = 0;
+}