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/react-native/ReactCommon/cxxreact/tests/jsbigstring.cpp

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <fcntl.h>
+#include <sys/mman.h>
+
+#include <cxxreact/JSBigString.h>
+#include <gtest/gtest.h>
+
+using namespace facebook::react;
+
+namespace {
+int tempFileFromString(std::string contents) {
+  const char* tmpDir = getenv("TMPDIR");
+  if (tmpDir == nullptr)
+    tmpDir = "/tmp";
+  std::string tmp{tmpDir};
+  tmp += "/temp.XXXXXX";
+
+  std::vector<char> tmpBuf{tmp.begin(), tmp.end()};
+  tmpBuf.push_back('\0');
+
+  const int fd = mkstemp(tmpBuf.data());
+  write(fd, contents.c_str(), contents.size() + 1);
+
+  return fd;
+}
+}; // namespace
+
+TEST(JSBigFileString, MapWholeFileTest) {
+  std::string data{"Hello, world"};
+  const auto size = data.length() + 1;
+
+  // Initialise Big String
+  int fd = tempFileFromString("Hello, world");
+  JSBigFileString bigStr{fd, size};
+
+  // Test
+  ASSERT_STREQ(data.c_str(), bigStr.c_str());
+}
+
+TEST(JSBigFileString, MapPartTest) {
+  std::string data{"Hello, world"};
+
+  // Sub-string to actually map
+  std::string needle{"or"};
+  off_t offset = data.find(needle);
+
+  // Initialise Big String
+  int fd = tempFileFromString(data);
+  JSBigFileString bigStr{fd, needle.size(), offset};
+
+  // Test
+  EXPECT_EQ(needle.length(), bigStr.size());
+  for (unsigned int i = 0; i < needle.length(); ++i) {
+    EXPECT_EQ(needle[i], bigStr.c_str()[i]);
+  }
+}