Hithomelabs/CFTunnels#114: Add JavaDoc to Mapping entity

src/main/java/com/hithomelabs/CFTunnels/Entity/Mapping.java

@@ -6,9 +6,29 @@ import lombok.Getter;
 import lombok.NoArgsConstructor;
 import lombok.Setter;
 
-
 import java.util.UUID;
 
+/**
+ * JPA Entity representing an ingress mapping configuration for a Cloudflare Tunnel.
+ * 
+ * <p>A mapping defines how incoming traffic should be routed through the tunnel
+ * to your internal services. It specifies the protocol, port, and subdomain
+ * where the service will be accessible.</p>
+ * 
+ * <p>Database Table: {@code mappings}</p>
+ * 
+ * <p><b>Example Usage:</b></p>
+ * <pre>
+ * Mapping mapping = new Mapping();
+ * mapping.setPort(8080);
+ * mapping.setProtocol(Protocol.HTTP);
+ * mapping.setSubdomain("api");
+ * </pre>
+ * 
+ * @see Tunnel
+ * @see Protocol
+ * @see Request
+ */
 @Entity
 @Getter
 @Setter
@@ -17,22 +37,50 @@ import java.util.UUID;
 @Table(name = "mappings")
 public class Mapping {
 
+    /**
+     * Unique identifier for this mapping (auto-generated UUID).
+     */
     @Id
     @GeneratedValue
     @Column(columnDefinition = "uuid", nullable = false, unique = true)
     private UUID id;
 
+    /**
+     * Port number where the internal service is running.
+     * 
+     * <p>Example: 8080 for a Spring Boot application's default port.</p>
+     */
     @Column(nullable = false)
     private int port;
 
+    /**
+     * Protocol used for the connection.
+     * 
+     * <p>Supported values: HTTP, HTTPS, TCP, SSH</p>
+     * @see Protocol
+     */
     @Enumerated(EnumType.STRING)
     @Column(length = 10, nullable = false)
     private Protocol protocol;
 
+    /**
+     * Subdomain prefix for accessing this service.
+     * 
+     * <p>Example: "api" would make the service available at
+     * {@code api.yourdomain.com}</p>
+     */
     @Column(length = 50, nullable = false)
     private String subdomain;
 
+    /**
+     * The tunnel this mapping is associated with.
+     * 
+     * <p>Each mapping belongs to exactly one tunnel.
+     * This is a lazy-loaded relationship to optimize performance.</p>
+     * 
+     * @see Tunnel
+     */
     @ManyToOne(fetch = FetchType.LAZY)
     @JoinColumn(name = "tunnel_id", nullable = false)
     private Tunnel tunnel;
-}
+}