Show and focus uninstall progress immediately after confirmation #1981

After confirming uninstall during a demo, the main app appeared unchanged for several seconds. The uninstall window was obscured until the app closed, making uninstall look broken.

Show focused uninstall progress immediately after confirmation, hide the normal app windows during handoff, and explicitly activate the relaunched uninstall window. Preserve safe teardown of in-flight operations before destructive cleanup.