Initial commit: RR3 Community Server with web admin panel

- ASP.NET Core 8 REST API server
- 12 API endpoints matching EA Synergy protocol
- SQLite database with Entity Framework Core
- Web admin panel with Bootstrap 5
- User, Catalog, Session, Purchase management
- Comprehensive documentation

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

RR3CommunityServer/Services/IServices.cs

@@ -0,0 +1,34 @@
+namespace RR3CommunityServer.Services;
+
+// Session Service
+public interface ISessionService
+{
+    Task<string> CreateSession(string? synergyId = null);
+    Task<bool> ValidateSession(string sessionId);
+    Task<string?> GetSynergyIdFromSession(string sessionId);
+}
+
+// User Service
+public interface IUserService
+{
+    Task<string> GetOrCreateDeviceId(string? existingDeviceId, string hardwareId);
+    Task<string> ValidateDeviceId(string deviceId);
+    Task<string> GetOrCreateAnonUid();
+    Task<string> GetOrCreateSynergyId(string deviceId);
+}
+
+// Catalog Service
+public interface ICatalogService
+{
+    Task<List<Models.CatalogItem>> GetAvailableItems();
+    Task<List<Models.CatalogCategory>> GetCategories();
+    Task<string> GetDownloadUrl(string itemId);
+}
+
+// DRM Service
+public interface IDrmService
+{
+    Task<string> GenerateNonce();
+    Task<List<Models.PurchasedItem>> GetPurchasedItems(string synergyId);
+    Task<bool> VerifyAndRecordPurchase(string synergyId, Models.PurchaseVerificationRequest request);
+}