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/inflight/README.md

@@ -0,0 +1,37 @@
+# inflight
+
+Add callbacks to requests in flight to avoid async duplication
+
+## USAGE
+
+```javascript
+var inflight = require('inflight')
+
+// some request that does some stuff
+function req(key, callback) {
+  // key is any random string.  like a url or filename or whatever.
+  //
+  // will return either a falsey value, indicating that the
+  // request for this key is already in flight, or a new callback
+  // which when called will call all callbacks passed to inflightk
+  // with the same key
+  callback = inflight(key, callback)
+
+  // If we got a falsey value back, then there's already a req going
+  if (!callback) return
+
+  // this is where you'd fetch the url or whatever
+  // callback is also once()-ified, so it can safely be assigned
+  // to multiple events etc.  First call wins.
+  setTimeout(function() {
+    callback(null, key)
+  }, 100)
+}
+
+// only assigns a single setTimeout
+// when it dings, all cbs get called
+req('foo', cb1)
+req('foo', cb2)
+req('foo', cb3)
+req('foo', cb4)
+```