feat(smart-app): implement complete mobile app MVP

- App.tsx: full navigation (Auth stack + Main tabs with 5 screens)
- Auth: LoginScreen, RegisterScreen, ForgotPasswordScreen
- HomeScreen: dashboard with IoT metrics, weather widget, alerts, quick actions, sensors
- MapScreen: interactive map with layer toggles (6 layers)
- MarketplaceScreen: categories (6), products (5), search
- ChatScreen: AI chat with quick prompts (4), bot responses
- ProfileScreen: user info, stats, menu (9 items), logout
- AlertsScreen: alert list with severity, acknowledge
- SensorsScreen: sensor list with type filters (6 types), search
- ZonesScreen: zone cards with stats
- SettingsScreen: language picker (FR/EN/ES/DE), privacy, about
- Stores: iotStore (sensors, zones, alerts), notificationStore, uiStore + i18n
- Hooks: useSensors, useAlerts, useNotifications, useLocation
- Components: Card, Button, LoadingSpinner, ErrorBoundary, Header
- Services: iotService, notificationService (with axios API client)
- Utils: formatters (temp, AQI, noise, dates), validators (email, password, IBAN)
- Theme: colors.ts with full design system (Blue Ocean palette)
- Ditto: fixed MongoDB connection, new JWT secrets, official gateway image

smart-app-city/frontend/node_modules/prompts/lib/util/entriesToDisplay.js

@@ -0,0 +1,21 @@
+'use strict';
+
+/**
+ * Determine what entries should be displayed on the screen, based on the
+ * currently selected index and the maximum visible. Used in list-based
+ * prompts like `select` and `multiselect`.
+ *
+ * @param {number} cursor the currently selected entry
+ * @param {number} total the total entries available to display
+ * @param {number} [maxVisible] the number of entries that can be displayed
+ */
+module.exports = (cursor, total, maxVisible)  => {
+  maxVisible = maxVisible || total;
+
+  let startIndex = Math.min(total- maxVisible, cursor - Math.floor(maxVisible / 2));
+  if (startIndex < 0) startIndex = 0;
+
+  let endIndex = Math.min(startIndex + maxVisible, total);
+
+  return { startIndex, endIndex };
+};