VoxIP Kiosk OS 1.0.0: Raspberry Pi kiosk with web management

Chromium kiosk without a desktop for the Raspberry Pi 3, a Flask web
interface on port 8080 (kiosk, system and network management), a
restricted root helper, network changes with automatic rollback, a
healthcheck timer, install/update/uninstall scripts and a pi-gen image
build.

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

image/stage-voxip/prerun.sh

@@ -0,0 +1,5 @@
+#!/bin/bash -e
+# Start from the root filesystem of the previous stage (stage2 = Raspberry Pi OS Lite).
+if [ ! -d "${ROOTFS_DIR}" ]; then
+	copy_previous
+fi