feat: implement Blazor web interface for GM session management

- Created GmRelay.Web project (Blazor Server)
- Created GmRelay.Shared library for domain models and rendering
- Refactored GmRelay.Bot to use the Shared library
- Integrated Telegram Login widget with server-side HMAC verification
- Added Dashboard, Group Details, and Edit Session pages
- Enabled bot notifications and in-place message updates from web actions
- Updated .NET Aspire orchestration and Docker Compose configuration

src/GmRelay.AppHost/Program.cs

@@ -8,4 +8,8 @@ builder.AddProject<Projects.GmRelay_Bot>("bot")
     .WithReference(postgres)
     .WaitFor(postgres);
 
+builder.AddProject<Projects.GmRelay_Web>("web")
+    .WithReference(postgres)
+    .WaitFor(postgres);
+
 builder.Build().Run();