Windows installer GUI tests

These tests install, update, start and uninstall the desktop app through the real MSI installer UI on a GitHub-hosted Windows runner. msi-scenarios.ps1 drives the installer dialogs and Explorer through UI Automation (wingui.psm1), takes screenshots, keeps the installer logs, and asserts what is on disk after each step. There is no local Windows harness: the tests run only in the windows-msi-gui-test workflow, which is started manually.

Running

Start the workflow from the Actions tab or with gh:

gh workflow run windows-msi-gui-test.yml -R <owner>/simplex-chat --ref <branch with the workflow> \
  -f scenario=all -f label="what this run checks" \
  -f new_msi_run_id=<run id of a workflow that uploaded the MSI as an artifact>

Input	Meaning
`scenario`	One scenario, `all` (every scenario except known issues) or `everything`.
`label`	Free text shown in the run name.
`new_msi_run_id`, `new_msi_artifact`	Run id and artifact name of the MSI under test.
`new_msi_url`	URL of the MSI under test, used when `new_msi_run_id` is empty (default: the v7.0.3 release).
`old_msi_url`	MSI installed before the update in `update-desktop` (default: the v7.0.2 release).
`patch_with_ref`	Branch whose `scripts/desktop/disable-msi-install-dir-wipe-windows.ps1` is applied to the MSI under test before the scenarios. Checks an MSI change in about 10 minutes without a Windows build.

The run uploads the artifact windows-gui-evidence:

checks.txt: one line per check, name = actual (expected X) PASS|FAIL, plus informational lines;
captions.tsv and numbered PNG screenshots (1024x768);
logs/: verbose msiexec logs (UTF-16) for every install and uninstall.

The job fails if any check fails or a dialog does not appear in time. A missing dialog is recorded as an Unexpected state screenshot.

gh run view --log can return an empty log; read it with gh api repos/<owner>/simplex-chat/actions/jobs/<job id>/logs.

Scenarios

Scenario	Steps	Expected
`uninstall-desktop`	Put user files on the Desktop, install into `Desktop\` (the installer warns that the folder exists), uninstall	User files and Desktop remain; `SimpleX.exe`, `app`, `runtime` are removed
`update-same-build`	Install into `Desktop\`, update through the installer UI to a copy of the same MSI with a higher version	User files remain; old files removed; the updated app starts
`default-folder`	Install into `C:\Program Files\SimpleX\`, start the app, uninstall	The app starts; the folder is removed
`profile-folder`	Install into the user profile folder, start the app, add user files there, uninstall	User files and every file in `%AppData%\SimpleX` remain
`appdata-folder`	The same with `%AppData%\` as the install folder	As above
`update-desktop` (known issue)	Install the old MSI into `Desktop\`, update to the MSI under test	User files remain. Fails while the old MSI deletes its install folder on removal

The update scenarios update the way the in-app updater does: msiexec /i with the full UI and the default folder. The higher-version copy for update-same-build is made by the script: it changes the product version, product code, package code, Upgrade rows and the versioned registry key of the MSI under test.

Notes

Before a fix, profile-folder and appdata-folder delete files of the runner's user profile; they run last.
The runner user is an administrator, so the installer does not show a UAC prompt.
Windows Installer keeps the MSI open after a COM call until the COM objects are released; Close-MsiHandles forces that before the file is opened again.