The close handler hides the BrowserWindow instead of destroying it, so
once closed, subsequent dock or Finder activations were no-ops because
the activate handler only created a new window when mainWindow === null.
Show + focus the existing window if it's hidden so relaunch behaves as
expected. Also add console.log breadcrumbs in DesktopLaunchGate so we
can diagnose why the chooser sometimes appears not to render.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>