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/dayjs/esm/locale/cv.js

@@ -0,0 +1,24 @@
+// Chuvash [cv]
+import dayjs from '../index';
+var locale = {
+  name: 'cv',
+  weekdays: 'вырсарникун_тунтикун_ытларикун_юнкун_кӗҫнерникун_эрнекун_шӑматкун'.split('_'),
+  months: 'кӑрлач_нарӑс_пуш_ака_май_ҫӗртме_утӑ_ҫурла_авӑн_юпа_чӳк_раштав'.split('_'),
+  weekStart: 1,
+  weekdaysShort: 'выр_тун_ытл_юн_кӗҫ_эрн_шӑм'.split('_'),
+  monthsShort: 'кӑр_нар_пуш_ака_май_ҫӗр_утӑ_ҫур_авн_юпа_чӳк_раш'.split('_'),
+  weekdaysMin: 'вр_тн_ыт_юн_кҫ_эр_шм'.split('_'),
+  ordinal: function ordinal(n) {
+    return n;
+  },
+  formats: {
+    LT: 'HH:mm',
+    LTS: 'HH:mm:ss',
+    L: 'DD-MM-YYYY',
+    LL: 'YYYY [ҫулхи] MMMM [уйӑхӗн] D[-мӗшӗ]',
+    LLL: 'YYYY [ҫулхи] MMMM [уйӑхӗн] D[-мӗшӗ], HH:mm',
+    LLLL: 'dddd, YYYY [ҫулхи] MMMM [уйӑхӗн] D[-мӗшӗ], HH:mm'
+  }
+};
+dayjs.locale(locale, null, true);
+export default locale;