Make deleteAppDataOnUninstall configurable

[igorgudelj]

Summary

• Add a nsis.delete_app_data_on_uninstall config option (defaults to false) so app developers can opt in to deleting %APPDATA%\{appName} on Windows uninstall
• The option is passed from config/nativephp.php → BuildCommand env var → electron-builder.mjs

The underlying NSIS template already skips deletion during updates (${ifNot} ${isUpdated}), so app data is preserved when updating to a new version.

Usage

In your app's config/nativephp.php:

'nsis' => [
    'delete_app_data_on_uninstall' => true,
],

Or via environment variable: NATIVEPHP_NSIS_DELETE_APP_DATA=true

Test plan

• Build a Windows NSIS installer with the option set to true
• Install the app and verify app data is created in %APPDATA%
• Uninstall the app and verify %APPDATA%\{appName} is deleted
• Build with the option set to false (default) and verify app data persists after uninstall
• Update the app (install over existing) and verify app data is preserved in both cases

[SRWieZ]

Thanks for your PR. I would prefer if it was configurable. This is a breaking change otherwise.

[igorgudelj]

Makes sense! I've updated the PR.

[simonhamp]

We don't need it but it would be great if we could get a test here. We don't need to manually verify that NSIS is deleting the files, just that the flag gets passed through correctly from config to the builder script, as this would help us spot if the config value or.env key get changed by mistake.

We can safely assume that Electron Builder's options handle the values correctly given that they follow the spec in their docs

[igorgudelj]

I've added the tests.