v0.1.0 - experimental test build

Test build - experimental, never run on hardware

Every line of code in this release was written by an AI coding agent
(OpenCode, model Space Bunny Free). There is no human-written code in it.

It has never been run on a Steam Deck. No gadget has been created, no frame
captured, no host enumerated. 40 unit tests pass, covering the parts that do not
need hardware: V4L2 struct layouts and ioctl encoding, player discovery,
command construction, and every process failure path.

What it does

Shows a USB capture adapter's input fullscreen on the Deck's panel.

other PC ──HDMI──▶ capture card ──USB──▶ Deck

The Deck is not a display adapter and cannot be made into one: Linux has no
DisplayPort or HDMI gadget, and the Deck's USB-C only sends video. What works is
the other direction, which is why nothing needs installing on the other machine.

Three things to try, in order

1. Plug a UVC capture adapter in and press Rescan. If nothing appears, that is
   the end of it — the adapter is the hard requirement.
2. The Diagnostics panel says which players were found and whether /dev/dri
   is present. Most SteamOS installs have mpv already.
3. "Draw on the Deck's panel" needs mpv and takes DRM away from gamescope, so it
   only works outside Game Mode. It is off by default because it is experimental.

If you report a problem

The most useful thing is the plugin log at
~/homebrew/logs/decky-display/, plus the Diagnostics panel contents.