Build the Microsoft.Extensions.DependencyInjection provider in App and resolve the view model and runtime factory from it, replacing the manual new MainWindow(trace) path. MainWindow now takes an injected ctor (view model, tracer, runtime factory, provider); window-tied services are produced by MainWindowRuntimeFactory once the window exists. On real shutdown MainWindow_Closed disposes the provider (which disposes the view model first, then domain services and tracer), while the minimize-to-tray branch returns before any teardown.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Add Microsoft.Extensions.DependencyInjection package and introduce an
IStartupTracer abstraction with NoOpStartupTracer (zero-overhead default)
and FileStartupTracer (renamed from WinUiStartupTrace). A StartupTracer
factory selects the implementation from environment configuration.
Consumers (App, MainWindow, MainWindowViewModel, SensorColumnMeasurer) now
depend on the non-nullable interface, removing null-conditional trace calls
and decoupling startup instrumentation from construction logic. No behavior
change: tracing still writes the same log when enabled.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
JMR-dev
