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/ReactCommon/cxxreact/SharedProxyCxxModule.h

@@ -0,0 +1,42 @@
+/*
+ * 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.
+ */
+
+#include <memory>
+
+#include <cxxreact/CxxModule.h>
+
+namespace facebook {
+namespace xplat {
+namespace module {
+
+// Allows a Cxx-module to be shared or reused across multiple React instances
+// Caveat: the setInstance call is not forwarded, so usages of getInstance
+// inside your module (e.g. dispatching events) will always be nullptr.
+class SharedProxyCxxModule : public CxxModule {
+ public:
+  explicit SharedProxyCxxModule(std::shared_ptr<CxxModule> shared)
+      : shared_(shared) {}
+
+  std::string getName() override {
+    return shared_->getName();
+  }
+
+  auto getConstants() -> std::map<std::string, folly::dynamic> override {
+    return shared_->getConstants();
+  }
+
+  auto getMethods() -> std::vector<Method> override {
+    return shared_->getMethods();
+  }
+
+ private:
+  std::shared_ptr<CxxModule> shared_;
+};
+
+} // namespace module
+} // namespace xplat
+} // namespace facebook