feat: add signed PostgreSQL release updates

oa-backend/src/main/java/com/kaidi/oa/domain/IpRegulationVersion.java

@@ -6,7 +6,7 @@ import jakarta.persistence.Entity;
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.GenerationType;
 import jakarta.persistence.Id;
-import jakarta.persistence.Lob;
+import jakarta.persistence.Column;
 import jakarta.persistence.Table;
 
 /**
@@ -29,7 +29,7 @@ public class IpRegulationVersion {
 
     private String action;
 
-    @Lob
+    @Column(columnDefinition = "TEXT")
     private String contentSnapshot;
 
     /** 修订说明 / 审批意见。 */