Undocumented apps: per-device filter and wider device column; presence for Skip USMT

- Source Devices in the undocumented-apps list filters by device name, like
  the software columns; Devices and the action column take less room.
- Drop the one-click documented pick (Documented + Only ticked does it).
- Stage legend underline spans label and number.
- Device details title stays on one line; the name truncates instead.
- Presence sweep also pings devices under Skip USMT tags.

README.md

@@ -53,8 +53,8 @@ a 1,300-device scope.
   *Not in SCCM*, *No DNS record*, or *Waiting for worker...* if it hasn't been looked up yet.
   The dialog refreshes in place when the worker finishes a cycle.
 - **Presence**: every ping is recorded, so each device shows when it was last online and how
-  many days it has been offline. Completed pairs, which skip network checks in the sweep, are
-  pinged hourly during business hours and at midnight to keep theirs current.
+  many days it has been offline. Completed pairs and Skip USMT devices, which skip network checks
+  in the sweep, are pinged hourly during business hours and at midnight to keep theirs current.
 - **Snapshots**: the last free space and scanstate / loadstate lines seen while a device was
   reachable are kept with their timestamps, and shown for completed migrations and offline
   devices instead of blanks.