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/Network/RCTDataRequestHandler.mm

@@ -0,0 +1,86 @@
+/*
+ * 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 <React/RCTDataRequestHandler.h>
+#import <ReactCommon/RCTTurboModule.h>
+
+#import "RCTNetworkPlugins.h"
+
+@interface RCTDataRequestHandler () <RCTTurboModule>
+@end
+
+@implementation RCTDataRequestHandler {
+  NSOperationQueue *_queue;
+}
+
+RCT_EXPORT_MODULE()
+
+- (void)invalidate
+{
+  [_queue cancelAllOperations];
+  _queue = nil;
+}
+
+- (BOOL)canHandleRequest:(NSURLRequest *)request
+{
+  return [request.URL.scheme caseInsensitiveCompare:@"data"] == NSOrderedSame;
+}
+
+- (NSOperation *)sendRequest:(NSURLRequest *)request withDelegate:(id<RCTURLRequestDelegate>)delegate
+{
+  // Lazy setup
+  if (!_queue) {
+    _queue = [NSOperationQueue new];
+    _queue.maxConcurrentOperationCount = 2;
+  }
+
+  __weak __block NSBlockOperation *weakOp;
+  __block NSBlockOperation *op = [NSBlockOperation blockOperationWithBlock:^{
+    // Get mime type
+    NSRange firstSemicolon = [request.URL.resourceSpecifier rangeOfString:@";"];
+    NSString *mimeType =
+        firstSemicolon.length ? [request.URL.resourceSpecifier substringToIndex:firstSemicolon.location] : nil;
+
+    // Send response
+    NSURLResponse *response = [[NSURLResponse alloc] initWithURL:request.URL
+                                                        MIMEType:mimeType
+                                           expectedContentLength:-1
+                                                textEncodingName:nil];
+
+    [delegate URLRequest:weakOp didReceiveResponse:response];
+
+    // Load data
+    NSError *error;
+    NSData *data = [NSData dataWithContentsOfURL:request.URL options:NSDataReadingMappedIfSafe error:&error];
+    if (data) {
+      [delegate URLRequest:weakOp didReceiveData:data];
+    }
+    [delegate URLRequest:weakOp didCompleteWithError:error];
+  }];
+
+  weakOp = op;
+  [_queue addOperation:op];
+  return op;
+}
+
+- (void)cancelRequest:(NSOperation *)op
+{
+  [op cancel];
+}
+
+- (std::shared_ptr<facebook::react::TurboModule>)getTurboModule:
+    (const facebook::react::ObjCTurboModule::InitParams &)params
+{
+  return nullptr;
+}
+
+@end
+
+Class RCTDataRequestHandlerCls(void)
+{
+  return RCTDataRequestHandler.class;
+}