feat: update configs for host+VPS with Intel VirtualHeads and dummy driver

- Host: 20-intel-virtual.conf with Driver intel + VirtualHeads 1
- VPS: xorg-dummy.service + rustdesk-dummy.service for CPU-only
- Updated README with dual setup (host Intel iGPU + VPS dummy)
- Verified: VIRTUAL1 primary after reboot, HDMI1 clone
- Verified: DUMMY0 primary on VPS without GPU

bin/vps-start-xorg.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+# Start Xorg with dummy driver for headless VPS
+export DISPLAY=:0
+export XAUTHORITY=${XAUTHORITY:-/run/user/0/.Xauthority}
+
+# Generate MIT magic cookie if needed
+if [ ! -s "$XAUTHORITY" ]; then
+    mkdir -p "$(dirname "$XAUTHORITY")"
+    touch "$XAUTHORITY"
+    xauth -f "$XAUTHORITY" generate :0 MIT-MAGIC-COOKIE-1 2>/dev/null || \
+        xauth -f "$XAUTHORITY" add :0 MIT-MAGIC-COOKIE-1 "$(xxd -l 16 -p /dev/urandom)" 2>/dev/null || true
+fi
+
+# Ensure socket directory
+mkdir -p /tmp/.X11-unix
+
+# Check if already running
+if pgrep -x "Xorg" >/dev/null 2>&1; then
+    echo "Xorg already running"
+    exit 0
+fi
+
+exec /usr/lib/xorg/Xorg :0 \
+    -nolisten tcp \
+    -nolisten local \
+    -config /etc/X11/xorg.conf.d/99-dummy.conf \
+    +extension GLX \
+    +extension RANDR \
+    +extension RENDER \
+    -novtswitch \
+    -keeptty