The previous approach used Builder::default_window_icon() which doesn't
exist in Tauri 2.10. Instead, set the icon via window.set_icon() in the
setup hook, and enable the "image-png" feature flag so Image::from_bytes
can decode the PNG icon at runtime.
Also change bundle identifier from "com.triple-c.app" to
"com.triple-c.desktop" to avoid conflicting with the .app bundle
extension on macOS.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>