Refactor SignalR client DI and config, add test factory
Refactored FruitBankSignalRClient construction to use DI and centralized configuration from appsettings.json across all platforms. Introduced TestSignalRClientFactory for consistent test setup. Added FruitBankHubConnectionExtensions for reusable SignalR connection and logging configuration. Updated Program.cs and MauiProgram.cs to register logger factories, log writers, and IHubConnectionBuilder via DI. Embedded appsettings.json in MAUI and updated .csproj references for build flexibility. No business logic changes; all updates are infrastructure and test setup.
- Switch FruitBankConstClient.BaseUrl to HTTPS for localhost.
- Pin DevExpress.Blazor to 25.1.3 in client project.
- Add Microsoft.Extensions.ObjectPool v9 to test project for SignalR.
- Reformat App.razor markup; comment out ResourcePreloader.
- Render @Body only if logged in or on login page in MainLayout.
- Redirect to /Login if not authenticated after auto-login.
- Add SandboxEndpointSimpleTests.cs for HTTP/SignalR endpoint tests against local sandbox.
Loretta