refactor(persistency): extract shared audit columns into AttributeAuditFields

SonarCloud flagged 5.6% new-code duplication (gate: <=3%) - the
is_deleted/created_at/created_by/updated_at/updated_by block was
copy-pasted identically across AttributeDefinition,
AttributeDefinitionScope, and AttributeValue.

Extracted into a @MappedSuperclass all three now extend; Hibernate
still maps the fields into each entity's own table exactly as before,
so no schema or behavior change.

Author: Filip-sz-informed

src/main/java/uk/gov/dbt/ndtp/ia/node/management/persistency/entity/AttributeAuditFields.java

@@ -0,0 +1,45 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * © Crown Copyright 2026. This work has been developed by the National Digital Twin Programme and is legally
+ * attributed to the Department for Business and Trade (UK) as the governing entity.
+ */
+
+package uk.gov.dbt.ndtp.ia.node.management.persistency.entity;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.MappedSuperclass;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Size;
+import java.sql.Timestamp;
+import lombok.Getter;
+import lombok.Setter;
+
+/**
+ * Shared soft-delete and audit columns for the policy attribute schema entities
+ * ({@link AttributeDefinition}, {@link AttributeDefinitionScope}, {@link AttributeValue}).
+ */
+@Getter
+@Setter
+@MappedSuperclass
+public abstract class AttributeAuditFields {
+
+    @NotNull
+    @Column(name = "is_deleted", nullable = false)
+    private Boolean isDeleted = false;
+
+    @NotNull
+    @Column(name = "created_at", nullable = false)
+    private Timestamp createdAt;
+
+    @Size(max = 255)
+    @NotNull
+    @Column(name = "created_by", nullable = false, length = 255)
+    private String createdBy;
+
+    @Column(name = "updated_at")
+    private Timestamp updatedAt;
+
+    @Size(max = 255)
+    @Column(name = "updated_by", length = 255)
+    private String updatedBy;
+}

src/main/java/uk/gov/dbt/ndtp/ia/node/management/persistency/entity/AttributeDefinition.java

@@ -9,7 +9,6 @@
 import jakarta.persistence.*;
 import jakarta.validation.constraints.NotNull;
 import jakarta.validation.constraints.Size;
-import java.sql.Timestamp;
 import lombok.Getter;
 import lombok.Setter;
 import org.hibernate.annotations.JdbcTypeCode;
@@ -19,7 +18,7 @@
 @Setter
 @Entity
 @Table(name = "attribute_definition")
-public class AttributeDefinition {
+public class AttributeDefinition extends AttributeAuditFields {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     @Column(name = "id", nullable = false)
@@ -67,24 +66,4 @@ public class AttributeDefinition {
     @NotNull
     @Column(name = "sensitive", nullable = false)
     private Boolean sensitive = false;
-
-    @NotNull
-    @Column(name = "is_deleted", nullable = false)
-    private Boolean isDeleted = false;
-
-    @NotNull
-    @Column(name = "created_at", nullable = false)
-    private Timestamp createdAt;
-
-    @Size(max = 255)
-    @NotNull
-    @Column(name = "created_by", nullable = false, length = 255)
-    private String createdBy;
-
-    @Column(name = "updated_at")
-    private Timestamp updatedAt;
-
-    @Size(max = 255)
-    @Column(name = "updated_by", length = 255)
-    private String updatedBy;
 }

src/main/java/uk/gov/dbt/ndtp/ia/node/management/persistency/entity/AttributeDefinitionScope.java

@@ -8,8 +8,6 @@
 
 import jakarta.persistence.*;
 import jakarta.validation.constraints.NotNull;
-import jakarta.validation.constraints.Size;
-import java.sql.Timestamp;
 import lombok.Getter;
 import lombok.Setter;
 import org.hibernate.annotations.JdbcTypeCode;
@@ -19,7 +17,7 @@
 @Setter
 @Entity
 @Table(name = "attribute_definition_scope")
-public class AttributeDefinitionScope {
+public class AttributeDefinitionScope extends AttributeAuditFields {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     @Column(name = "id", nullable = false)
@@ -42,24 +40,4 @@ public class AttributeDefinitionScope {
     @JdbcTypeCode(SqlTypes.JSON)
     @Column(name = "default_value")
     private String defaultValue;
-
-    @NotNull
-    @Column(name = "is_deleted", nullable = false)
-    private Boolean isDeleted = false;
-
-    @NotNull
-    @Column(name = "created_at", nullable = false)
-    private Timestamp createdAt;
-
-    @Size(max = 255)
-    @NotNull
-    @Column(name = "created_by", nullable = false, length = 255)
-    private String createdBy;
-
-    @Column(name = "updated_at")
-    private Timestamp updatedAt;
-
-    @Size(max = 255)
-    @Column(name = "updated_by", length = 255)
-    private String updatedBy;
 }

src/main/java/uk/gov/dbt/ndtp/ia/node/management/persistency/entity/AttributeValue.java

@@ -8,8 +8,6 @@
 
 import jakarta.persistence.*;
 import jakarta.validation.constraints.NotNull;
-import jakarta.validation.constraints.Size;
-import java.sql.Timestamp;
 import lombok.Getter;
 import lombok.Setter;
 import org.hibernate.annotations.JdbcTypeCode;
@@ -19,7 +17,7 @@
 @Setter
 @Entity
 @Table(name = "attribute_value")
-public class AttributeValue {
+public class AttributeValue extends AttributeAuditFields {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     @Column(name = "id", nullable = false)
@@ -44,24 +42,4 @@ public class AttributeValue {
     @JdbcTypeCode(SqlTypes.JSON)
     @Column(name = "value", nullable = false)
     private String value;
-
-    @NotNull
-    @Column(name = "is_deleted", nullable = false)
-    private Boolean isDeleted = false;
-
-    @NotNull
-    @Column(name = "created_at", nullable = false)
-    private Timestamp createdAt;
-
-    @Size(max = 255)
-    @NotNull
-    @Column(name = "created_by", nullable = false, length = 255)
-    private String createdBy;
-
-    @Column(name = "updated_at")
-    private Timestamp updatedAt;
-
-    @Size(max = 255)
-    @Column(name = "updated_by", length = 255)
-    private String updatedBy;
 }