Add user profile and avatar upload feature

web/backend/Features/Features.Users/Repository/IUserAvatarRepository.cs

@@ -0,0 +1,14 @@
+using Domain.Entities;
+
+namespace Features.Auth.Repository;
+
+/// <summary>
+///     Repository for persisting user avatar records.
+/// </summary>
+public interface IUserAvatarRepository
+{
+    /// <summary>
+    ///     Persists <paramref name="avatar" />, replacing any existing avatar for the same user profile.
+    /// </summary>
+    Task SaveAsync(UserAvatar avatar, CancellationToken cancellationToken);
+}