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/React/CxxModule/RCTCxxModule.mm

@@ -0,0 +1,87 @@
+/*
+ * 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.
+ */
+
+#import "RCTCxxModule.h"
+
+#import <React/RCTBridge.h>
+#import <React/RCTFollyConvert.h>
+#import <React/RCTLog.h>
+#import <cxxreact/CxxModule.h>
+
+#import "RCTCxxMethod.h"
+
+using namespace facebook::react;
+
+@implementation RCTCxxModule {
+  std::unique_ptr<facebook::xplat::module::CxxModule> _module;
+}
+
++ (NSString *)moduleName
+{
+  return @"";
+}
+
++ (BOOL)requiresMainQueueSetup
+{
+  return NO;
+}
+
+- (void)lazyInit
+{
+  if (!_module) {
+    _module = [self createModule];
+
+    if (_module) {
+      RCTAssert(
+          [RCTBridgeModuleNameForClass([self class]) isEqualToString:@(_module->getName().c_str())],
+          @"CxxModule class name %@ does not match runtime name %s",
+          RCTBridgeModuleNameForClass([self class]),
+          _module->getName().c_str());
+    }
+  }
+}
+
+- (std::unique_ptr<facebook::xplat::module::CxxModule>)createModule
+{
+  RCTAssert(NO, @"Subclass %@ must override createModule", [self class]);
+  return nullptr;
+}
+
+- (NSArray<id<RCTBridgeMethod>> *)methodsToExport
+{
+  [self lazyInit];
+  if (!_module) {
+    return nil;
+  }
+
+  NSMutableArray *moduleMethods = [NSMutableArray new];
+  for (const auto &method : _module->getMethods()) {
+    [moduleMethods addObject:[[RCTCxxMethod alloc] initWithCxxMethod:method]];
+  }
+  return moduleMethods;
+}
+
+- (NSDictionary<NSString *, id> *)constantsToExport
+{
+  return [self getConstants];
+}
+
+- (NSDictionary<NSString *, id> *)getConstants
+{
+  [self lazyInit];
+  if (!_module) {
+    return nil;
+  }
+
+  NSMutableDictionary *moduleConstants = [NSMutableDictionary new];
+  for (const auto &c : _module->getConstants()) {
+    moduleConstants[@(c.first.c_str())] = convertFollyDynamicToId(c.second);
+  }
+  return moduleConstants;
+}
+
+@end