WiFi screen: Ctrl+Alt+Super+W, gated by the unlock PIN/password

The WiFi screen now opens with Ctrl+Alt+Super+W, which is easier to
press than the five-key chord. The Shift+W+S+F+H chord and
Ctrl+Alt+Shift+Super+W are removed. Fn isn't part of the combo: most
keyboards never send it to the computer.

With password protection on, the screen asks for the unlock code: the
PIN pad for a PIN, a password field for a password. It shares the
lock screen's wrong-code slowdown. With protection off, it falls back
to the hidden-sites PIN as before. The lock screen's check now goes
through the same checkCode() helper.

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

lib/provision.sh

@@ -221,7 +221,7 @@ provision_configure_display() {
     log_success "Display configured"
 }
 
-# The kiosk app's WiFi screen (Ctrl+Alt+Shift+Super+W) - joining WiFi from
+# The kiosk app's WiFi screen (Ctrl+Alt+Super+W) - joining WiFi from
 # the kiosk itself when the console is switched off. The app runs as the
 # kiosk user; the netplan write is done by this one root helper, which
 # the kiosk user may run through sudo and nothing else (it only does
@@ -239,7 +239,7 @@ provision_install_wifi_helper() {
         sudo mkdir -p "$SUDOERS_D_DIR"
         sudo install -m 0440 -o root -g root "$tmp" "$SUDOERS_D_DIR/kiosk-wifi"
     else
-        log_warning "Couldn't set up the kiosk WiFi screen's permission - Ctrl+Alt+Shift+Super+W won't be able to connect"
+        log_warning "Couldn't set up the kiosk WiFi screen's permission - Ctrl+Alt+Super+W won't be able to connect"
     fi
     rm -f "$tmp"
 }