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/unique-filename/README.md

@@ -0,0 +1,34 @@
+unique-filename
+===============
+
+Generate a unique filename for use in temporary directories or caches.
+
+```js
+const uniqueFilename = require('unique-filename')
+
+// returns something like: '/tmp/c5b28f47'
+const randomTmpfile = uniqueFilename(os.tmpdir())
+
+// returns something like: '/tmp/my-test-51a7b48d'
+const randomPrefixedTmpfile = uniqueFilename(os.tmpdir(), 'my-test')
+
+// returns something like: '/my-tmp-dir/testing-7ddd44c0'
+const uniqueTmpfile = uniqueFilename('/my-tmp-dir', 'testing', '/my/thing/to/uniq/on')
+```
+
+### uniqueFilename(*dir*, *fileprefix*, *uniqstr*) → String
+
+Returns the full path of a unique filename that looks like:
+`dir/prefix-7ddd44c0`
+or `dir/7ddd44c0`
+
+*dir* – The path you want the filename in. `os.tmpdir()` is a good choice for this.
+
+*fileprefix* – A string to append prior to the unique part of the filename.
+The parameter is required if *uniqstr* is also passed in but is otherwise
+optional and can be `undefined`/`null`/`''`. If present and not empty
+then this string plus a hyphen are prepended to the unique part.
+
+*uniqstr* – Optional, if not passed the unique part of the resulting
+filename will be random.  If passed in it will be generated from this string
+in a reproducible way.