fix: verify work during continuously hidden guest intervals

docs/verification.md

@@ -18,7 +18,10 @@ The smoke test builds a private input helper with an ordinary evdev/pc105 US
 keyboard map. It boots two tiny counter workloads from separate scratch qcow2
 disks, connects two fullscreen viewers, and checks reserved switching/recovery,
 manual USB selection, explicit reconnect and independent QMP lifecycles.
-Guest memory counters must advance and QEMU PIDs must remain unchanged through
+After each confirmed workspace switch, the hidden guest is sampled across a
+half-second interval with no focus changes, switches or reconnects; the check is
+then repeated with the other guest hidden. `result.json` records both intervals.
+Guest memory counters must advance and QEMU PIDs remain unchanged through
 switching. Viewer protocol logs must show no reconnection during switching.
 A test-only `ToggleKeybinds` action and F12 marker establish native labwc
 keybinding inhibition before checking the production reserved bindings. Those
@@ -28,7 +31,8 @@ extra controls are absent from the production session configuration. See the
 for native `ToggleKeybinds` behavior.
 
 USB acceptance checks the actual selector window title, holds the modifiers
-through opening, releases them inside the modal dialog, then switches again.
+through opening, releases them inside the modal dialog, then asserts fresh
+keyboard leave/enter transitions for both Right and Left switches.
 QEMU's USB device list must stay unchanged without a selection. Both viewer
 USB filters deny automatic hotplug and connection redirection. This check does
 not attach a physical USB device or prove guest driver behavior.
@@ -38,6 +42,17 @@ forwarding an event to the guest. Upstream keyboard grabs remove the GTK
 application accelerator group; without this adaptation, the configured USB
 shortcut reaches the viewer but does not open its selector.
 
+The pinned labwc 0.20.2 runtime has no documented runtime XWayland-disable
+option. This native-Wayland probe sets `WLR_XWAYLAND=/bin/false` so no X server
+is launched, and explicitly disables activation-environment updates. It can
+still log an occupied X socket while wlroots reserves a display number. Only
+`[xwayland/sockets.c] Failed to bind socket ... Address already in use` is
+classified as expected noise in `result.json`; any other compositor `[ERROR]`
+fails the probe. Full logs remain available. This classification does not
+suppress viewer errors or compiler/test diagnostics. The viewer build's upstream
+Meson boolean-check and compiler-warning-option guidance are build noise; the four-test
+result, compiler errors and process exit status remain the build acceptance gate.
+
 ## Installed guest workflow
 
 `--iso` is optional. Attach or detach media only while the VM is stopped:
@@ -78,8 +93,11 @@ Only `add` reads distribution defaults. Explicit `--network`, `--bridge`,
 not change. `--defaults PATH` selects another preferences file for development.
 Missing defaults use developer preferences; unknown or invalid fields fail
 before creating a profile. Dimensions are integers from 1 to 16384, refresh is
-an integer from 0 to 1000000 mHz. Nonzero refresh requires the tracked patched
-QEMU provided by `dev/tools.nix` and distribution packaging.
+zero for automatic refresh or an integer from 50000 to 255000 mHz, matching
+the vertical range descriptor limits. This bound does not establish every
+resolution/refresh combination; pixel-clock and horizontal timing limits are
+mode-dependent and the verified target remains 1920×1080/144000 mHz. Nonzero
+refresh requires the tracked patched QEMU provided by `dev/tools.nix` and distribution packaging.
 
 The patch keeps the requested refresh through frontend resizing and extends
 EDID monitor ranges to include the generated preferred mode. To verify the