Refactor app architecture and clean local artifacts

Backend/Domain/RiskFlag.cs

@@ -14,6 +14,7 @@ public sealed class RiskFlag
     public string CreatedFromIp { get; set; } = string.Empty;
     public string UserAgent { get; set; } = string.Empty;
     public string MetadataJson { get; set; } = "{}";
+    public string? ReviewNote { get; set; }
     public string? ReviewedByTwitchId { get; set; }
     public DateTimeOffset CreatedAt { get; set; }
     public DateTimeOffset? ReviewedAt { get; set; }