The Settings portal reads appearance exclusively from the compositor's
theme control socket and falls back to defaults when no compositor is
reachable, so the contract test could no longer assert appearance from an
on-disk KDL document.
Add a fixtures/theme_owner.py peer that speaks the theme IPC framing and
publishes schema-v2 snapshots, point the test at a private runtime socket,
and clear WAYLAND_DISPLAY and WAYLAND_SOCKET so the backend cannot reach a
host compositor. Assert the initial values, the SettingChanged payload
after a republish, and that ReadAll matches the published snapshot, then
confirm an invalid local document does not disturb portal-owned
appearance.
Samuel Onoja
b105ea8ef9