Lifts Bannerlator's Linux/gamescope runtime out into an app of its own: the
Wayland compositor, the proot session, the runtime installer, the fake-evdev
controller path and the PulseAudio server, with none of the Wine, container or
store machinery around them.
One activity installs the runtime from the same winlator-contents catalog and a
second one runs the session: compositor on a SurfaceView, gamescope and Valve's
native arm64 client under proot, a physical pad republished into the fake-input
rings, and the session's milestones on screen until the first frame arrives.
