Arming the built-in xHCI root hubs made them wake on hub-level events
(USB-C PD negotiation, SD card reader, internal peripherals), causing the
laptop to immediately self-wake from suspend. Drop the root-hub rule and arm
only the keyboard leaf by VID:PID; a leaf device's remote-wakeup propagates
through the hub without the hub's own wakeup flag being set.
Add a udev rule (t480UsbWakeup) that arms USB remote-wakeup for a keyboard
on the built-in xHCI controller (00:14.0), so pressing a key wakes the T480
from S3. The dock connects over the Thunderbolt-3 controller (3c:00.0), which
powers down in S3 and cannot detect a cold replug, so dock-connected input
cannot wake the machine after an unplug-triggered suspend; a built-in-port
keyboard can. Match the keyboard by VID:PID since its USB bus path is unstable.
Also wires up the logind lid-switch policy (suspend undocked, ignore docked)
for the clamshell workflow.
ahmza