Add self-service account management commands (delete, update username/email/password/profile)

web/backend/Features/Features.Auth/Commands/UpdateProfile/UpdateProfileCommand.cs

@@ -0,0 +1,19 @@
+using Features.Auth.Dtos;
+using MediatR;
+
+namespace Features.Auth.Commands.UpdateProfile;
+
+/// <summary>
+///     Updates the non-credential profile fields (first name, last name, date of birth) of the given
+///     user account.
+/// </summary>
+/// <param name="UserAccountId">
+///     The authenticated caller's own ID, extracted from the access token -- never bind this from
+///     client-supplied input.
+/// </param>
+public record UpdateProfileCommand(
+    Guid UserAccountId,
+    string FirstName,
+    string LastName,
+    DateTime DateOfBirth
+) : IRequest<UpdateProfilePayload>;