Add Steam OpenID authentication

microservices/AuthApi/Models/Dto.cs

@@ -7,3 +7,11 @@ public class RefreshRequest  { public string Username { get; set; } = ""; public
 public class UpdateProfileRequest { public string? DisplayName { get; set; } public string? Email { get; set; } }
 public class ChangePasswordRequest { public string CurrentPassword { get; set; } = ""; public string NewPassword { get; set; } = ""; }
 public class DeleteAccountRequest { public string Password { get; set; } = ""; public string Confirmation { get; set; } = ""; }
+public class CompleteSteamRequest
+{
+    public string TransactionId { get; set; } = "";
+    public string Action { get; set; } = "";
+    public string Username { get; set; } = "";
+    public string? Email { get; set; }
+    public string Password { get; set; } = "";
+}

microservices/AuthApi/Models/SteamAuthTransaction.cs

@@ -0,0 +1,14 @@
+using MongoDB.Bson.Serialization.Attributes;
+
+namespace AuthApi.Models;
+
+public class SteamAuthTransaction
+{
+    [BsonId]
+    public string Id { get; set; } = "";
+    public string Status { get; set; } = "pending";
+    public string? SteamId { get; set; }
+    public string? UserId { get; set; }
+    public DateTime CreatedUtc { get; set; }
+    public DateTime ExpiresUtc { get; set; }
+}

microservices/AuthApi/Models/User.cs

@@ -15,4 +15,5 @@ public class User
     public DateTime? CreatedUtc { get; set; }
     public string? RefreshToken { get; set; }
     public DateTime? RefreshTokenExpiry { get; set; }
+    public string? SteamId { get; set; }
 }