On IoT LTSC winget is absent, so Process.Start('winget') throws Win32Exception
('cannot find the file specified') rather than returning non-zero. That throw
propagated out of InstallAsync and failed the entire Apply ('Configuration failed').
AppInstaller is now fully exception-safe: a TryRunAsync wrapper converts launch
throws into a failed run, winget is resolved defensively (PATH -> bootstrap+re-probe
-> WindowsApps alias path) and when unavailable the installer skips apps and marks
them not-installed instead of throwing. Per-app launch throws are isolated too.
Two new tests cover probe-throws-skips and per-app-throw-isolated.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
