Frametop: a multi-screen desktop and universal 3D mouse for the Steam Frame

Several KDE Plasma screens floating in SteamVR, each a real monitor of any
resolution and shape, shown by our own compositor (ft-screens), with a
layout, wrist pinning, and visibility modes; a Bluetooth mouse that drives
all of SteamVR as a room-anchored 3D pointer (input relay, ft-pointer
helper, ft_pointer SteamVR driver); two settings apps; and Bluetooth LE
fixes. Installs on the headset with ./install.sh.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

pointer/probe/build.sh

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+# Build vrprobe in the dev container on the Frame (pointer/probe/build/vrprobe).
+set -euo pipefail
+root=$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)
+"$root/scripts/sync.sh" >/dev/null
+exec "$root/scripts/frame.sh" -C pointer/probe 'set -e; mkdir -p build
+g++ -std=c++17 -O2 -Wall -I/opt/steamvr/tools/hellovr_vulkan_linux/src/openvr/headers -I../common \
+  -o build/vrprobe vrprobe.cpp -L/opt/steamvr/bin/linuxarm64 -lopenvr_api -Wl,-rpath,/opt/steamvr/bin/linuxarm64
+echo "built build/vrprobe"'