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/graphql/jsutils/keyMap.js.flow

@@ -0,0 +1,35 @@
+// @flow strict
+import type { ObjMap } from './ObjMap';
+
+/**
+ * Creates a keyed JS object from an array, given a function to produce the keys
+ * for each value in the array.
+ *
+ * This provides a convenient lookup for the array items if the key function
+ * produces unique results.
+ *
+ *     const phoneBook = [
+ *       { name: 'Jon', num: '555-1234' },
+ *       { name: 'Jenny', num: '867-5309' }
+ *     ]
+ *
+ *     // { Jon: { name: 'Jon', num: '555-1234' },
+ *     //   Jenny: { name: 'Jenny', num: '867-5309' } }
+ *     const entriesByName = keyMap(
+ *       phoneBook,
+ *       entry => entry.name
+ *     )
+ *
+ *     // { name: 'Jenny', num: '857-6309' }
+ *     const jennyEntry = entriesByName['Jenny']
+ *
+ */
+export default function keyMap<T>(
+  list: $ReadOnlyArray<T>,
+  keyFn: (item: T) => string,
+): ObjMap<T> {
+  return list.reduce((map, item) => {
+    map[keyFn(item)] = item;
+    return map;
+  }, Object.create(null));
+}