Report guest HID keyboard LED state from LGInput to LGIdd and
publish it with the LGMP input endpoint status.
Forward SPICE modifier updates through the same provider state so evdev
can synchronize physical keyboard LEDs across transport changes and
reconnects.
Bump the versioned pipe and KVMFR input status contracts for the new
feedback state.
Accept earlier LGMP input status versions without LED feedback so the
client retains input while the guest driver is being upgraded.
Introduce LG_InputOps and route keyboard and mouse input through the
active video transport when it provides an input backend.
Keep SPICE as the fallback and force it while the SPICE display is
active. Add atomic shared/exclusive locking for safe backend changes.
