Add real first-time provisioning to install.sh (v2.14.0)

Until now ./install.sh only managed an already-installed kiosk;
ubuntu-based-kiosk.sh was still the only path from a bare Ubuntu Server
box to a running one. install.sh now provisions from scratch too:
packages, kiosk user, Node.js/Electron, LightDM+Openbox autologin,
audio/video/HDMI/power-button hardware setup, and the firewall, then
hands off to the already-migrated Core Settings/Advanced menus for
initial configuration instead of reimplementing that logic again.

- lib/provision.sh: the new provisioning flow, built mostly by calling
  existing menus (core_settings_menu, emergency hotspot, virtual
  consoles) - cuts it to ~300 lines against the legacy script's
  ~4,000-line first_time_install().
- lib/electron.sh: electron_install_binary() extracted out of
  menus/advanced_electron.sh so provisioning and the existing "Fix
  blank screen" action share one implementation.
- kiosk-app/ and provision/files/: the Electron app source and every
  system template file, extracted byte-for-byte out of
  ubuntu-based-kiosk.sh's heredocs into real files.
- Found and fixed a bash set -e gotcha along the way: testing a
  multi-statement function as an if-condition (`if ! some_func; then`)
  silently exempts everything inside that function from set -e for the
  duration of the call. Fixed in the new provisioning code and in
  menus/advanced_electron.sh's pre-existing repair action, which had
  the same shape.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VfsFSoRqfbRG7XAg5RoE7e

provision/files/usr/local/bin/kiosk-audio-route.sh

@@ -0,0 +1,36 @@
+#!/bin/bash
+# Assumes DISPLAY/XAUTHORITY are set (for xrandr) and pactl already has a
+# working PipeWire/pulse socket for the invoking context.
+
+QUERY=$(xrandr --query 2>/dev/null)
+[ -z "$QUERY" ] && exit 0
+
+PRIMARY_OUTPUT=$(echo "$QUERY" | awk '/ primary/{print $1; exit}')
+[ -z "$PRIMARY_OUTPUT" ] && exit 0
+
+EXTERNAL_CONNECTED=$(echo "$QUERY" | awk -v p="$PRIMARY_OUTPUT" '/ connected/ && $1!=p{f=1} END{print (f==1)?"yes":"no"}')
+
+HDMI_SINK=$(pactl list sinks short 2>/dev/null | awk 'tolower($2) ~ /hdmi/{print $2; exit}')
+NON_HDMI_SINK=$(pactl list sinks short 2>/dev/null | awk 'tolower($2) !~ /hdmi/{print $2; exit}')
+
+route_to() {
+  local sink="$1" label="$2"
+  if [ -z "$sink" ]; then
+    logger "KIOSK: no $label audio sink found, leaving routing unchanged"
+    return
+  fi
+  pactl set-default-sink "$sink" 2>/dev/null \
+    && logger "KIOSK: audio routed to $label sink ($sink)" \
+    || logger "KIOSK: failed to route audio to $label sink ($sink)"
+  pactl list sink-inputs short 2>/dev/null | awk '{print $1}' | while read -r sid; do
+    pactl move-sink-input "$sid" "$sink" 2>/dev/null
+  done
+  pactl set-sink-volume "$sink" 100% 2>/dev/null
+  pactl set-sink-mute "$sink" 0 2>/dev/null
+}
+
+if [ "$EXTERNAL_CONNECTED" = "yes" ]; then
+  route_to "$HDMI_SINK" "HDMI"
+else
+  route_to "$NON_HDMI_SINK" "built-in"
+fi