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/fs-extra/lib/json/index.js

@@ -0,0 +1,16 @@
+'use strict'
+
+const u = require('universalify').fromCallback
+const jsonFile = require('./jsonfile')
+
+jsonFile.outputJson = u(require('./output-json'))
+jsonFile.outputJsonSync = require('./output-json-sync')
+// aliases
+jsonFile.outputJSON = jsonFile.outputJson
+jsonFile.outputJSONSync = jsonFile.outputJsonSync
+jsonFile.writeJSON = jsonFile.writeJson
+jsonFile.writeJSONSync = jsonFile.writeJsonSync
+jsonFile.readJSON = jsonFile.readJson
+jsonFile.readJSONSync = jsonFile.readJsonSync
+
+module.exports = jsonFile

smart-app-city/frontend/node_modules/fs-extra/lib/json/jsonfile.js

@@ -0,0 +1,12 @@
+'use strict'
+
+const u = require('universalify').fromCallback
+const jsonFile = require('jsonfile')
+
+module.exports = {
+  // jsonfile exports
+  readJson: u(jsonFile.readFile),
+  readJsonSync: jsonFile.readFileSync,
+  writeJson: u(jsonFile.writeFile),
+  writeJsonSync: jsonFile.writeFileSync
+}

smart-app-city/frontend/node_modules/fs-extra/lib/json/output-json-sync.js

@@ -0,0 +1,18 @@
+'use strict'
+
+const fs = require('graceful-fs')
+const path = require('path')
+const mkdir = require('../mkdirs')
+const jsonFile = require('./jsonfile')
+
+function outputJsonSync (file, data, options) {
+  const dir = path.dirname(file)
+
+  if (!fs.existsSync(dir)) {
+    mkdir.mkdirsSync(dir)
+  }
+
+  jsonFile.writeJsonSync(file, data, options)
+}
+
+module.exports = outputJsonSync

smart-app-city/frontend/node_modules/fs-extra/lib/json/output-json.js

@@ -0,0 +1,27 @@
+'use strict'
+
+const path = require('path')
+const mkdir = require('../mkdirs')
+const pathExists = require('../path-exists').pathExists
+const jsonFile = require('./jsonfile')
+
+function outputJson (file, data, options, callback) {
+  if (typeof options === 'function') {
+    callback = options
+    options = {}
+  }
+
+  const dir = path.dirname(file)
+
+  pathExists(dir, (err, itDoes) => {
+    if (err) return callback(err)
+    if (itDoes) return jsonFile.writeJson(file, data, options, callback)
+
+    mkdir.mkdirs(dir, err => {
+      if (err) return callback(err)
+      jsonFile.writeJson(file, data, options, callback)
+    })
+  })
+}
+
+module.exports = outputJson