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/cross-spawn/lib/util/escape.js

@@ -0,0 +1,47 @@
+'use strict';
+
+// See http://www.robvanderwoude.com/escapechars.php
+const metaCharsRegExp = /([()\][%!^"`<>&|;, *?])/g;
+
+function escapeCommand(arg) {
+    // Escape meta chars
+    arg = arg.replace(metaCharsRegExp, '^$1');
+
+    return arg;
+}
+
+function escapeArgument(arg, doubleEscapeMetaChars) {
+    // Convert to string
+    arg = `${arg}`;
+
+    // Algorithm below is based on https://qntm.org/cmd
+    // It's slightly altered to disable JS backtracking to avoid hanging on specially crafted input
+    // Please see https://github.com/moxystudio/node-cross-spawn/pull/160 for more information
+
+    // Sequence of backslashes followed by a double quote:
+    // double up all the backslashes and escape the double quote
+    arg = arg.replace(/(?=(\\+?)?)\1"/g, '$1$1\\"');
+
+    // Sequence of backslashes followed by the end of the string
+    // (which will become a double quote later):
+    // double up all the backslashes
+    arg = arg.replace(/(?=(\\+?)?)\1$/, '$1$1');
+
+    // All other backslashes occur literally
+
+    // Quote the whole thing:
+    arg = `"${arg}"`;
+
+    // Escape meta chars
+    arg = arg.replace(metaCharsRegExp, '^$1');
+
+    // Double escape meta chars if necessary
+    if (doubleEscapeMetaChars) {
+        arg = arg.replace(metaCharsRegExp, '^$1');
+    }
+
+    return arg;
+}
+
+module.exports.command = escapeCommand;
+module.exports.argument = escapeArgument;

smart-app-city/frontend/node_modules/cross-spawn/lib/util/readShebang.js

@@ -0,0 +1,23 @@
+'use strict';
+
+const fs = require('fs');
+const shebangCommand = require('shebang-command');
+
+function readShebang(command) {
+    // Read the first 150 bytes from the file
+    const size = 150;
+    const buffer = Buffer.alloc(size);
+
+    let fd;
+
+    try {
+        fd = fs.openSync(command, 'r');
+        fs.readSync(fd, buffer, 0, size, 0);
+        fs.closeSync(fd);
+    } catch (e) { /* Empty */ }
+
+    // Attempt to extract shebang (null is returned if not a shebang)
+    return shebangCommand(buffer.toString());
+}
+
+module.exports = readShebang;

smart-app-city/frontend/node_modules/cross-spawn/lib/util/resolveCommand.js

@@ -0,0 +1,52 @@
+'use strict';
+
+const path = require('path');
+const which = require('which');
+const getPathKey = require('path-key');
+
+function resolveCommandAttempt(parsed, withoutPathExt) {
+    const env = parsed.options.env || process.env;
+    const cwd = process.cwd();
+    const hasCustomCwd = parsed.options.cwd != null;
+    // Worker threads do not have process.chdir()
+    const shouldSwitchCwd = hasCustomCwd && process.chdir !== undefined && !process.chdir.disabled;
+
+    // If a custom `cwd` was specified, we need to change the process cwd
+    // because `which` will do stat calls but does not support a custom cwd
+    if (shouldSwitchCwd) {
+        try {
+            process.chdir(parsed.options.cwd);
+        } catch (err) {
+            /* Empty */
+        }
+    }
+
+    let resolved;
+
+    try {
+        resolved = which.sync(parsed.command, {
+            path: env[getPathKey({ env })],
+            pathExt: withoutPathExt ? path.delimiter : undefined,
+        });
+    } catch (e) {
+        /* Empty */
+    } finally {
+        if (shouldSwitchCwd) {
+            process.chdir(cwd);
+        }
+    }
+
+    // If we successfully resolved, ensure that an absolute path is returned
+    // Note that when a custom `cwd` was used, we need to resolve to an absolute path based on it
+    if (resolved) {
+        resolved = path.resolve(hasCustomCwd ? parsed.options.cwd : '', resolved);
+    }
+
+    return resolved;
+}
+
+function resolveCommand(parsed) {
+    return resolveCommandAttempt(parsed) || resolveCommandAttempt(parsed, true);
+}
+
+module.exports = resolveCommand;