Classify configured devices by keyboard and pointer capability so
automatic keyboard capture leaves relative pointer devices with the
display server.
Run descriptor, grab, physical-state, and LED operations on one worker.
Marshal normalized events through each display server's event loop and
serialize ownership changes with per-lane barriers.
Fall back whole lanes to native input when an evdev cohort cannot be
owned, and retry missing or removed devices without disabling the rest.
Handle report framing, SYN_DROPPED, high-resolution wheels, queue
overflow, held-state cleanup, and guest-driven keyboard LEDs. Restore
host LEDs and kernel grabs during teardown.
Re-evaluate capture when the active input transport changes.
Track unexpected loss of an admitted fallback independently from normal
stop and UUID revocation. Terminate once both primary and fallback
sessions have disappeared, regardless of notification order.
Make shutdown terminal so concurrent disconnect handling cannot replace
it with restart or running state.
