feat: add QET Xephyr launch script

scripts/qet-xephyr.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+# Launch QElectroTech in a nested Xephyr X server with Openbox
+# Works around Wayland drag-and-drop issue in QET
+
+XEPHYR_PID=""
+
+cleanup() {
+    kill $XEPHYR_PID 2>/dev/null
+    exit 0
+}
+trap cleanup SIGINT SIGTERM
+
+Xephyr -screen 1920x1080 :1 -title QET -br &
+XEPHYR_PID=$!
+
+sleep 1
+DISPLAY=:1 openbox &
+sleep 0.5
+DISPLAY=:1 qelectrotech &
+
+wait $XEPHYR_PID