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/react-native/ReactAndroid/cmake-utils/folly-flags.cmake

@@ -0,0 +1,23 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+cmake_minimum_required(VERSION 3.13)
+set(CMAKE_VERBOSE_MAKEFILE on)
+
+# This CMake file exposes the Folly Flags that all the libraries should use when
+# compiling/linking against a dependency which requires folly.
+
+SET(folly_FLAGS
+        -DFOLLY_NO_CONFIG=1
+        -DFOLLY_HAVE_CLOCK_GETTIME=1
+        -DFOLLY_USE_LIBCPP=1
+        -DFOLLY_CFG_NO_COROUTINES=1
+        -DFOLLY_MOBILE=1
+        -DFOLLY_HAVE_RECVMMSG=1
+        -DFOLLY_HAVE_PTHREAD=1
+        # Once we target android-23 above, we can comment
+        # the following line. NDK uses GNU style stderror_r() after API 23.
+        -DFOLLY_HAVE_XSI_STRERROR_R=1
+        )