feat: add admin page

lib/views/settings_view.dart

@@ -8,6 +8,7 @@ import 'package:provider/provider.dart';
 import 'package:sentry_flutter/sentry_flutter.dart';
 
 import '../models/settings.dart';
+import '../viewmodels/admin_pin_view_model.dart';
 import '../utils/app_update_util.dart';
 import '../utils/navigation.dart';
 import '../viewmodels/pin_lock_view_model.dart';
@@ -33,6 +34,7 @@ class _SettingsScreenViewState extends State<SettingsScreenView> {
     WidgetsBinding.instance.addPostFrameCallback((_) {
       context.read<SettingsViewModel>().ensureLoaded();
       context.read<PinLockViewModel>().ensureLoaded();
+      context.read<AdminPinViewModel>().ensureLoaded();
       _loadVersion();
     });
   }
@@ -190,11 +192,62 @@ class _SettingsScreenViewState extends State<SettingsScreenView> {
     }
   }
 
+  Future<void> _configureAdminPin() async {
+    final l10n = AppLocalizations.of(context);
+    final adminPinViewModel = context.read<AdminPinViewModel>();
+
+    if (!adminPinViewModel.isPinSet) {
+      final pin = await _promptPin(l10n.setAdminPin, hint: l10n.fourDigits);
+      if (pin == null) return;
+
+      if (pin.length != 4) {
+        _showError(l10n.pinExactlyFour);
+        return;
+      }
+
+      final success = await adminPinViewModel.setPin(pin);
+      if (!success) {
+        _showError(l10n.localizedError(adminPinViewModel.errorMessage));
+        return;
+      }
+
+      adminPinViewModel.lock();
+      return;
+    }
+
+    final current = await _promptPin(l10n.enterCurrentAdminPin);
+    if (current == null) return;
+
+    final newPin = await _promptPin(
+      l10n.enterNewAdminPin,
+      hint: l10n.fourDigits,
+    );
+    if (newPin == null) return;
+
+    if (newPin.length != 4) {
+      _showError(l10n.pinExactlyFour);
+      return;
+    }
+
+    final success = await adminPinViewModel.changePin(
+      currentPin: current,
+      newPin: newPin,
+    );
+
+    if (!success) {
+      _showError(l10n.localizedError(adminPinViewModel.errorMessage));
+      return;
+    }
+
+    adminPinViewModel.lock();
+  }
+
   @override
   Widget build(BuildContext context) {
     final l10n = AppLocalizations.of(context);
     final settingsViewModel = context.watch<SettingsViewModel>();
     final pinLockViewModel = context.watch<PinLockViewModel>();
+    final adminPinViewModel = context.watch<AdminPinViewModel>();
 
     return Scaffold(
       appBar: AppBar(
@@ -207,9 +260,13 @@ class _SettingsScreenViewState extends State<SettingsScreenView> {
       body: Builder(
         builder: (context) {
           final isLoading =
-              settingsViewModel.isLoading || pinLockViewModel.isLoading;
+              settingsViewModel.isLoading ||
+              pinLockViewModel.isLoading ||
+              adminPinViewModel.isLoading;
           final hasLoaded =
-              settingsViewModel.hasLoaded && pinLockViewModel.hasLoaded;
+              settingsViewModel.hasLoaded &&
+              pinLockViewModel.hasLoaded &&
+              adminPinViewModel.hasLoaded;
 
           if (isLoading && !hasLoaded) {
             return const Center(
@@ -251,6 +308,14 @@ class _SettingsScreenViewState extends State<SettingsScreenView> {
                       title: l10n.changePin,
                       onTap: _changePin,
                     ),
+                  _SettingsTile(
+                    icon: Icons.admin_panel_settings_outlined,
+                    title: l10n.adminPin,
+                    subtitle: adminPinViewModel.isPinSet
+                        ? l10n.adminPinConfigured
+                        : l10n.adminPinNotSet,
+                    onTap: _configureAdminPin,
+                  ),
                 ],
               ),
               _SettingsSection(