t480: wake from suspend via built-in-USB keyboard

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.

modules/hosts/t480/default.nix

@@ -19,6 +19,12 @@
       obsidian
       discord
       gaming
+      winbox
+      cad
+      prusa-slicer
+      netops
+      via
+      t480UsbWakeup
     ];
   };
 }