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/expo-image-picker/ios/ImagePickerHandler.swift

@@ -0,0 +1,121 @@
+// Copyright 2022-present 650 Industries. All rights reserved.
+
+import PhotosUI
+
+/**
+ Protocol that describes scenarios we care about while the user is picking media.
+ */
+protocol OnMediaPickingResultHandler {
+  @available(iOS 14, *)
+  func didPickMultipleMedia(selection: [PHPickerResult])
+  func didPickMedia(mediaInfo: MediaInfo)
+  func didCancelPicking()
+}
+
+/**
+ This class is responsible for responding to any events that are happening in `UIImagePickerController`.
+ It then forwards them back in unified way via `OnMediaPickingResultHandler`.
+
+ The functionality of this delegate is separated from the main module class for two reasons:
+ 1) main module cannot inherit from `NSObject` (and that's required by three protocols we must conform to),
+ because it already inherits from `Module` class and Swift language does not allow multiple inheritance,
+ 2) it separates some logic from the main module class and hopefully makes it cleaner.
+ */
+internal class ImagePickerHandler: NSObject,
+                                   PHPickerViewControllerDelegate,
+                                   UINavigationControllerDelegate,
+                                   UIImagePickerControllerDelegate,
+                                   UIAdaptivePresentationControllerDelegate {
+  private let onMediaPickingResultHandler: OnMediaPickingResultHandler
+  private let hideStatusBarWhenPresented: Bool
+  private var statusBarVisibilityController = StatusBarVisibilityController()
+
+  init(onMediaPickingResultHandler: OnMediaPickingResultHandler, hideStatusBarWhenPresented: Bool) {
+    self.onMediaPickingResultHandler = onMediaPickingResultHandler
+    self.hideStatusBarWhenPresented = hideStatusBarWhenPresented
+  }
+
+  private func handlePickedMedia(mediaInfo: MediaInfo) {
+    statusBarVisibilityController.maybeRestoreStatusBarVisibility()
+    onMediaPickingResultHandler.didPickMedia(mediaInfo: mediaInfo)
+  }
+
+  @available(iOS 14, *)
+  private func handlePickedMedia(selection: [PHPickerResult]) {
+    statusBarVisibilityController.maybeRestoreStatusBarVisibility()
+    onMediaPickingResultHandler.didPickMultipleMedia(selection: selection)
+  }
+
+  private func handlePickingCancellation() {
+    statusBarVisibilityController.maybeRestoreStatusBarVisibility()
+    onMediaPickingResultHandler.didCancelPicking()
+  }
+
+  // MARK: - UIImagePickerControllerDelegate
+
+  func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: MediaInfo) {
+    DispatchQueue.main.async {
+      picker.dismiss(animated: true) { [weak self] in
+        self?.handlePickedMedia(mediaInfo: info)
+      }
+    }
+  }
+
+  func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
+    DispatchQueue.main.async {
+      picker.dismiss(animated: true) { [weak self] in
+        self?.handlePickingCancellation()
+      }
+    }
+  }
+
+  // MARK: - PHPickerViewControllerDelegate
+
+  @available(iOS 14, *)
+  func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
+    DispatchQueue.main.async {
+      picker.dismiss(animated: true) { [weak self] in
+        // The PHPickerViewController returns empty collection when canceled
+        if results.isEmpty {
+          self?.handlePickingCancellation()
+        } else {
+          self?.handlePickedMedia(selection: results)
+        }
+      }
+    }
+  }
+
+  // MARK: - UIAdaptivePresentationControllerDelegate
+
+  func presentationControllerDidDismiss(_ presentationController: UIPresentationController) {
+    handlePickingCancellation()
+  }
+
+  // MARK: - UINavigationControllerDelegate
+
+  func navigationController(_ navigationController: UINavigationController, willShow viewController: UIViewController, animated: Bool) {
+    statusBarVisibilityController.maybePreserveVisibilityAndHideStatusBar(hideStatusBarWhenPresented)
+  }
+}
+
+/**
+ Protocol that is a common type for supported picker controllers.
+ */
+internal protocol PickerUIController: UIViewController {
+  func setResultHandler(_ handler: ImagePickerHandler)
+}
+
+extension UIImagePickerController: PickerUIController {
+  func setResultHandler(_ handler: ImagePickerHandler) {
+    self.delegate = handler
+    self.presentationController?.delegate = handler
+  }
+}
+
+@available(iOS 14, *)
+extension PHPickerViewController: PickerUIController {
+  func setResultHandler(_ handler: ImagePickerHandler) {
+    self.delegate = handler
+    self.presentationController?.delegate = handler
+  }
+}