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/buffer-alloc-unsafe/index.js

@@ -0,0 +1,17 @@
+function allocUnsafe (size) {
+  if (typeof size !== 'number') {
+    throw new TypeError('"size" argument must be a number')
+  }
+
+  if (size < 0) {
+    throw new RangeError('"size" argument must not be negative')
+  }
+
+  if (Buffer.allocUnsafe) {
+    return Buffer.allocUnsafe(size)
+  } else {
+    return new Buffer(size)
+  }
+}
+
+module.exports = allocUnsafe

smart-app-city/frontend/node_modules/buffer-alloc-unsafe/package.json

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+{
+  "name": "buffer-alloc-unsafe",
+  "version": "1.1.0",
+  "license": "MIT",
+  "repository": "LinusU/buffer-alloc-unsafe",
+  "files": [
+    "index.js"
+  ],
+  "scripts": {
+    "test": "standard && node test"
+  },
+  "devDependencies": {
+    "standard": "^7.1.2"
+  },
+  "keywords": [
+    "allocUnsafe",
+    "allocate",
+    "buffer allocUnsafe",
+    "buffer unsafe allocate",
+    "buffer",
+    "ponyfill",
+    "unsafe allocate"
+  ]
+}

smart-app-city/frontend/node_modules/buffer-alloc-unsafe/readme.md

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+# Buffer Alloc Unsafe
+
+A [ponyfill](https://ponyfill.com) for `Buffer.allocUnsafe`.
+
+Works as Node.js: `v7.0.0` <br>
+Works on Node.js: `v0.10.0`
+
+## Installation
+
+```sh
+npm install --save buffer-alloc-unsafe
+```
+
+## Usage
+
+```js
+const allocUnsafe = require('buffer-alloc-unsafe')
+
+console.log(allocUnsafe(10))
+//=> <Buffer 78 0c 80 03 01 00 00 00 05 00>
+
+console.log(allocUnsafe(10))
+//=> <Buffer 58 ed bf 5f ff 7f 00 00 01 00>
+
+console.log(allocUnsafe(10))
+//=> <Buffer 50 0c 80 03 01 00 00 00 0a 00>
+
+allocUnsafe(-10)
+//=> RangeError: "size" argument must not be negative
+```
+
+## API
+
+### allocUnsafe(size)
+
+- `size` &lt;Integer&gt; The desired length of the new `Buffer`
+
+Allocates a new *non-zero-filled* `Buffer` of `size` bytes. The `size` must be
+less than or equal to the value of `buffer.kMaxLength` and greater than or equal
+to zero. Otherwise, a `RangeError` is thrown.
+
+## See also
+
+- [buffer-alloc](https://github.com/LinusU/buffer-alloc) A ponyfill for `Buffer.alloc`
+- [buffer-fill](https://github.com/LinusU/buffer-fill) A ponyfill for `Buffer.fill`
+- [buffer-from](https://github.com/LinusU/buffer-from) A ponyfill for `Buffer.from`