Add security on endpoints and handle 403 responses.

sportshub-domain/src/main/java/org/sportshub/domain/user/model/User.java

@@ -1,8 +1,10 @@
 package org.sportshub.domain.user.model;
 
+import java.util.List;
 import java.util.UUID;
 
 public record User(
     UUID id,
-    String password
+    String password,
+    List<UserRole> roles
 ) {}

sportshub-domain/src/main/java/org/sportshub/domain/user/model/UserRole.java

@@ -0,0 +1,6 @@
+package org.sportshub.domain.user.model;
+
+public enum UserRole {
+    STANDARD,
+    ADMIN
+}