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/obj/Debug/net8.0/RR3CommunityServer.RazorAssemblyInfo.cache

@@ -0,0 +1 @@
+d5ac7ab69059af111e9d7125adeb7b174ca570725d4b64a544cca7bd11ac7ca0