963c406f33
The virtual Steam Deck is validated glass-to-glass on a Deck: it appears as a
distinct second Steam controller, a held A drives Steam's overlay ("Resume
Game"), and a button press registers in a real game (confirmed in-game).
gadget_preferred() now defaults ON for SteamOS hosts (/etc/os-release ID=steamos
or ID_LIKE), OFF elsewhere where the universal UHID path stays the default;
PUNKTFUNK_STEAM_GADGET=1/0 forces it. A Deck-as-host with a physical Deck never
reaches this path — resolve_gamepad's conflict gate degrades SteamDeck → DualSense
first, so the two-Deck case never happens in production (it was only a test-rig
confound on the dev Deck).
The feature is complete: a virtual Steam Deck that Steam Input recognizes +
promotes, churn-free, with input flowing to games. Workspace clippy/fmt/test
green. Not pushed.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>