Address PR #310 review feedback on the public profile page

web/backend/Features/Features.Users/Dtos/UserDtoMapper.cs

@@ -0,0 +1,11 @@
+using Domain.Entities;
+
+namespace Features.Users.Dtos;
+
+/// <summary>Converts user domain entities into API response models.</summary>
+public static class UserDtoMapper
+{
+    /// <summary>Converts a user account into its public-profile representation.</summary>
+    public static PublicUserProfileDto ToPublicProfileDto(this UserAccount user) =>
+        new(user.UserAccountId, user.Username, user.FirstName, user.LastName, user.CreatedAt);
+}

web/backend/Features/Features.Users/Dtos/UserDtos.cs

@@ -0,0 +1,10 @@
+namespace Features.Users.Dtos;
+
+/// <summary>Represents the subset of a user account that is safe to expose on a public profile.</summary>
+public record PublicUserProfileDto(
+    Guid UserAccountId,
+    string Username,
+    string FirstName,
+    string LastName,
+    DateTime CreatedAt
+);