mpv owns the macOS Now Playing session (it plays the audio), and an
unbundled binary renders as a blank placeholder for the source-app icon.
macOS has no public API for a third party to claim session ownership
(MPNowPlayingSession is iOS-only; the private MRMediaRemoteSetNowPlayingApplication
was removed from the shared cache), so instead we make the OWNING process
carry our bundle: the darwin tarball now includes PodTui.app with mpv copied
into Contents/MacOS. AudioPlayer resolves the sibling mpv first (falling
back to PATH), LaunchServices attributes the process to com.mikefreno.podtui,
and Control Center shows the PodTui icon + name with podcast cover art.
AppIcon.icns generated from the Xcode icon-composer exports.
