Add hibernate-jpa module: 40 runnable Hibernate 7 / JPA interview answers on PostgreSQL 16

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01Cfo2K4u4rF18QsPXPFnytf

hibernate-jpa/src/main/java/lab/hibernate/model/SetItem.java

@@ -0,0 +1,37 @@
+package lab.hibernate.model;
+
+import jakarta.persistence.*;
+import java.util.Objects;
+
+/** hashCode built on the generated id: the classic trap. */
+@Entity
+public class SetItem {
+    @Id
+    @GeneratedValue
+    public Long id;
+    public String name;
+
+    protected SetItem() {}
+
+    public SetItem(String name) {
+        this.name = name;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        return o instanceof SetItem other && Objects.equals(id, other.id);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(id);
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public String getName() {
+        return name;
+    }
+}