Refactor app architecture and clean local artifacts

Backend/Repositories/IRiskFlagRepository.cs

@@ -0,0 +1,17 @@
+using Backend.Domain;
+
+namespace Backend.Repositories;
+
+public interface IRiskFlagRepository
+{
+    Task<bool> ExistsOpenRecentAsync(
+        int? seasonId,
+        string? twitchUserId,
+        string source,
+        string type,
+        string clientIp,
+        DateTimeOffset threshold,
+        CancellationToken cancellationToken = default);
+
+    void Add(RiskFlag riskFlag);
+}