Install WiFi tools (wpasupplicant, iw) in the base kiosk install

A default Ubuntu Server 26.04 install only gets wpasupplicant/iw when
WiFi is configured in the installer's network screen (they're not in the
server manifest otherwise). Without them netplan can't join a WiFi
network and Core Settings -> WiFi stops at "No WiFi tools found" - which
is exactly the offline-first case: install with no network, then use the
kiosk's WiFi menu to connect.

- Add wpasupplicant and iw to PROVISION_APT_PACKAGES, so first boot
  installs them in step 1 (from the offline bundle when there's no
  internet) - before Core Settings -> WiFi is offered. +1.6 MB in the
  bundle.
- wifi_menu installs them itself (via run_with_offline_fallback) if
  they're missing, instead of erroring with an apt command to run.

Bundle rebuilt: contains wpasupplicant and iw.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Cjz8a58eB5P9sUweqd3NHm

menus/wifi.sh

@@ -31,6 +31,18 @@ wifi_menu() {
     echo " ═══ WIFI CONFIGURATION ═══"
     echo
 
+    # netplan needs wpa_supplicant to join WiFi at all; iw/wpa_cli scan.
+    # Missing on a server install that skipped WiFi in the installer -
+    # install them here (from the offline bundle if there's no internet,
+    # which is exactly the situation this menu is usually opened in).
+    if ! command -v wpa_supplicant &>/dev/null || ! command -v iw &>/dev/null; then
+        echo "WiFi support (wpasupplicant, iw) isn't installed yet - installing..."
+        if ! run_with_offline_fallback sudo apt install -y wpasupplicant iw; then
+            log_error "Couldn't install WiFi support (needs internet, wired, or an --offline install ISO)"
+            return 1
+        fi
+    fi
+
     local has_tools=false
     if command -v nmcli &>/dev/null || command -v iw &>/dev/null || command -v wpa_cli &>/dev/null; then
         has_tools=true