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/Libraries/Utilities/defineLazyObjectProperty.js

@@ -0,0 +1,66 @@
+/**
+ * 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.
+ *
+ * @format
+ * @flow strict
+ */
+
+'use strict';
+
+/**
+ * Defines a lazily evaluated property on the supplied `object`.
+ */
+function defineLazyObjectProperty<T>(
+  object: interface {},
+  name: string,
+  descriptor: {
+    get: () => T,
+    enumerable?: boolean,
+    writable?: boolean,
+    ...
+  },
+): void {
+  const {get} = descriptor;
+  const enumerable = descriptor.enumerable !== false;
+  const writable = descriptor.writable !== false;
+
+  let value;
+  let valueSet = false;
+  function getValue(): T {
+    // WORKAROUND: A weird infinite loop occurs where calling `getValue` calls
+    // `setValue` which calls `Object.defineProperty` which somehow triggers
+    // `getValue` again. Adding `valueSet` breaks this loop.
+    if (!valueSet) {
+      // Calling `get()` here can trigger an infinite loop if it fails to
+      // remove the getter on the property, which can happen when executing
+      // JS in a V8 context.  `valueSet = true` will break this loop, and
+      // sets the value of the property to undefined, until the code in `get()`
+      // finishes, at which point the property is set to the correct value.
+      valueSet = true;
+      setValue(get());
+    }
+    return value;
+  }
+  function setValue(newValue: T): void {
+    value = newValue;
+    valueSet = true;
+    Object.defineProperty(object, name, {
+      value: newValue,
+      configurable: true,
+      enumerable,
+      writable,
+    });
+  }
+
+  Object.defineProperty(object, name, {
+    get: getValue,
+    set: setValue,
+    configurable: true,
+    enumerable,
+  });
+}
+
+module.exports = defineLazyObjectProperty;