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/dotenv-expand/lib/main.d.ts

@@ -0,0 +1,50 @@
+// TypeScript Version: 3.0
+/// <reference types="node" />
+
+export interface DotenvPopulateInput {
+  [name: string]: string;
+}
+
+export interface DotenvParseInput {
+  [name: string]: string;
+}
+
+export interface DotenvParseOutput {
+  [name: string]: string;
+}
+
+export interface DotenvExpandOptions {
+  error?: Error;
+
+  /**
+   * Default: `process.env`
+   *
+   * Specify an object to write your secrets to. Defaults to process.env environment variables.
+   *
+   * example: `const processEnv = {}; require('dotenv').config({ processEnv: processEnv })`
+   */
+  processEnv?: DotenvPopulateInput;
+
+  /**
+   * Default: `object`
+   *
+   * Object coming from dotenv's parsed result.
+   */
+  parsed?: DotenvParseInput;
+}
+
+export interface DotenvExpandOutput {
+  error?: Error;
+  parsed?: DotenvParseOutput;
+}
+
+/**
+ * Adds variable expansion on top of dotenv.
+ *
+ * See https://docs.dotenv.org
+ *
+ * @param options - additional options. example: `{ processEnv: {}, error: null, parsed: { { KEY: 'value' } }`
+ * @returns an object with a `parsed` key if successful or `error` key if an error occurred. example: { parsed: { KEY: 'value' } }
+ *
+ */
+export function expand(options?: DotenvExpandOptions): DotenvExpandOutput

smart-app-city/frontend/node_modules/dotenv-expand/lib/main.js

@@ -0,0 +1,86 @@
+'use strict'
+
+// * /
+// *   (\\)?            # is it escaped with a backslash?
+// *   (\$)             # literal $
+// *   (?!\()           # shouldnt be followed by parenthesis
+// *   (\{?)            # first brace wrap opening
+// *   ([\w.]+)         # key
+// *   (?::-((?:\$\{(?:\$\{(?:\$\{[^}]*\}|[^}])*}|[^}])*}|[^}])+))? # optional default nested 3 times
+// *   (\}?)            # last brace warp closing
+// * /xi
+
+const DOTENV_SUBSTITUTION_REGEX = /(\\)?(\$)(?!\()(\{?)([\w.]+)(?::?-((?:\$\{(?:\$\{(?:\$\{[^}]*\}|[^}])*}|[^}])*}|[^}])+))?(\}?)/gi
+
+function _resolveEscapeSequences (value) {
+  return value.replace(/\\\$/g, '$')
+}
+
+function interpolate (value, processEnv, parsed) {
+  return value.replace(DOTENV_SUBSTITUTION_REGEX, (match, escaped, dollarSign, openBrace, key, defaultValue, closeBrace) => {
+    if (escaped === '\\') {
+      return match.slice(1)
+    } else {
+      if (processEnv[key]) {
+        if (processEnv[key] === parsed[key]) {
+          return processEnv[key]
+        } else {
+          // scenario: PASSWORD_EXPAND_NESTED=${PASSWORD_EXPAND}
+          return interpolate(processEnv[key], processEnv, parsed)
+        }
+      }
+
+      if (parsed[key]) {
+        // avoid recursion from EXPAND_SELF=$EXPAND_SELF
+        if (parsed[key] !== value) {
+          return interpolate(parsed[key], processEnv, parsed)
+        }
+      }
+
+      if (defaultValue) {
+        if (defaultValue.startsWith('$')) {
+          return interpolate(defaultValue, processEnv, parsed)
+        } else {
+          return defaultValue
+        }
+      }
+
+      return ''
+    }
+  })
+}
+
+function expand (options) {
+  let processEnv = process.env
+  if (options && options.processEnv != null) {
+    processEnv = options.processEnv
+  }
+
+  for (const key in options.parsed) {
+    let value = options.parsed[key]
+
+    const inProcessEnv = Object.prototype.hasOwnProperty.call(processEnv, key)
+    if (inProcessEnv) {
+      if (processEnv[key] === options.parsed[key]) {
+        // assume was set to processEnv from the .env file if the values match and therefore interpolate
+        value = interpolate(value, processEnv, options.parsed)
+      } else {
+        // do not interpolate - assume processEnv had the intended value even if containing a $.
+        value = processEnv[key]
+      }
+    } else {
+      // not inProcessEnv so assume interpolation for this .env key
+      value = interpolate(value, processEnv, options.parsed)
+    }
+
+    options.parsed[key] = _resolveEscapeSequences(value)
+  }
+
+  for (const processKey in options.parsed) {
+    processEnv[processKey] = options.parsed[processKey]
+  }
+
+  return options
+}
+
+module.exports.expand = expand