* feat: stand in for /dev/uinput so Steam Input's virtual pads reach games
* feat: present the pad to the Steam client as a Steam Deck controller over hidraw
* docs: log the uinput stand-in and the Steam Deck controller
* feat: feed the handheld's gyro and accelerometer to the Steam Deck controller
* feat: let the Steam page choose between the Steam Deck controller and the Xbox 360 pad
* feat: Deck back grips and trackpads on the second screen
* fix: serialize ring teardown with its writers, fall back to the Xbox pad when the Deck cannot be set up, and read motion only for a Deck
* fix: keep the second screen's choice through sleep and bring it back on wake
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.