* feat: run SteamOS PipeWire and WirePlumber for gamescope screen capture
* feat: hardware Remote Play encoding through MediaCodec behind Steam's V4L2 stage
* feat: deliver Remote Play touches to gamescope as touches
* feat: route game audio through PulseAudio while a Remote Play client is connected
* fix: keep the Remote Play marker when a forked child closes the encoder
* fix: allow standalone preload tests without V4L2 encoder hook
