Windows Installer: optional removal of user data on uninstall

[Copilot]

Uninstalling OneWare Studio always left %APPDATA%\OneWareStudio and %USERPROFILE%\OneWareStudio behind. This adds an opt-in step to delete both, without ever touching them during updates.

UI (RemoveUserDataDlg.wxs, UI.wxs, Common.wxl)

• New dialog with a checkbox bound to the public property REMOVEUSERDATA, unchecked by default.
• Reached in both uninstall paths:
  • MSI run directly: MaintenanceTypeDlg → Remove → new dialog → VerifyReadyDlg (via a higher-Order Publish overriding the default navigation).
  • Apps & Features / Control Panel (Preselected): sequenced in InstallUISequence before ProgressDlg, conditioned on Installed AND Preselected AND REMOVE~="ALL" AND NOT PATCH AND NOT UPGRADINGPRODUCTCODE.

Removal (StudioComponents.wxs)

• New UserDataCleanupComponent (HKLM registry keypath) using util:RemoveFolderEx from the already-referenced Util extension. The folder properties use environment variables, which the custom action expands in the user context:

<Property Id="ONEWAREAPPDATAFOLDER" Value="%APPDATA%\OneWareStudio" />
<Property Id="ONEWAREDOCUMENTSFOLDER" Value="%USERPROFILE%\OneWareStudio" />
...
<util:RemoveFolderEx Id="RemoveAppDataFolder" On="uninstall"
    Property="ONEWAREAPPDATAFOLDER"
    Condition="REMOVEUSERDATA = &quot;1&quot; AND NOT UPGRADINGPRODUCTCODE" />

Update safety

• Major upgrades uninstall the old package via RemoveExistingProducts with no UI and UPGRADINGPRODUCTCODE set, so the property is never set and the condition additionally excludes that case.
• Silent uninstalls keep data unless REMOVEUSERDATA=1 is passed explicitly.

Paths mirror OneWare.Core/Services/Paths.cs (AppDataDirectory, DocumentsDirectory); custom locations set via ONEWARE_DIR / ONEWARE_APPDATA_DIR are intentionally not touched.

Note: WiX authoring only compiles/links on Linux — the generated MSI itself has not been exercised on Windows, so the dialog flow is worth a manual check.

• Fixes Windows Installer: Option to remove everything #340