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/wcwidth/Readme.md

@@ -0,0 +1,33 @@
+# wcwidth
+
+Determine columns needed for a fixed-size wide-character string
+
+----
+
+wcwidth is a simple JavaScript port of [wcwidth](http://man7.org/linux/man-pages/man3/wcswidth.3.html) implemented in C by Markus Kuhn.
+
+JavaScript port [originally](https://github.com/mycoboco/wcwidth.js) written by Woong Jun <woong.jun@gmail.com> (http://code.woong.org/)
+
+## Example
+
+```js
+'한'.length    // => 1
+wcwidth('한');   // => 2
+
+'한글'.length    // => 2
+wcwidth('한글'); // => 4
+```
+
+`wcwidth()` and its string version, `wcswidth()` are defined by IEEE Std
+1002.1-2001, a.k.a. POSIX.1-2001, and return the number of columns used
+to represent the given wide character and string.
+
+Markus's implementation assumes the wide character given to those
+functions to be encoded in ISO 10646, which is almost true for
+JavaScript's characters.
+
+[Further explaination here](docs)
+
+## License
+
+MIT