Web UI login with the kiosk's PIN/password; shortcuts list on the Sites page

When the kiosk's password protection is on, the Web UI now asks for the same
PIN/password the lock screen uses: random session cookie (12 h, HttpOnly,
SameSite=Strict), the lock screen's wrong-code slowdown, sessions end when
the kiosk's code changes, sign out. With protection off nothing changes.
The Sites page (Web UI and terminal menu) lists the back/forward/home and
site-switching keys.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013wi3ZQveYdjfcrEsyazq32

webui/lib/config.js

@@ -179,4 +179,17 @@ function saveConfig(patch) {
     return loadConfig();
 }
 
-module.exports = { loadConfig, saveConfig, CONFIG_PATH, SCALAR_DEFAULTS };
+// What the Web UI login needs: whether the kiosk's password protection is
+// on and the stored SHA-256 of its unlock code (the same one the lock screen
+// checks). Only used server-side to verify a login - never sent to a browser.
+function readLockSettings() {
+    const existing = readExisting();
+    const hash = typeof existing.lockoutPassword === 'string' ? existing.lockoutPassword : '';
+    return {
+        enabled: existing.enablePasswordProtection === true && hash.length > 0,
+        hash,
+        codeType: existing.lockoutCodeType === 'pin' ? 'pin' : 'password',
+    };
+}
+
+module.exports = { loadConfig, saveConfig, readLockSettings, hashPassword, CONFIG_PATH, SCALAR_DEFAULTS };