Add request logging mode, dark mode, Account hub, profile, vehicle CRUD, cards view

- Client: logRequests option + redacted request/response logging (setLogRequests to
  toggle at runtime); enabled via app extra.debugHttp for on-device 401 debugging
- Dark mode (persisted) via ThemeProvider + React Navigation theme
- New "Account" tab: Profile (view), Vehicles (full CRUD), Payment methods (view-only),
  About, dark-mode + request-logging toggles, sign out

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/App.tsx

@@ -2,15 +2,18 @@ import React from 'react';
 import { StatusBar } from 'expo-status-bar';
 import { SafeAreaProvider } from 'react-native-safe-area-context';
 import { AuthProvider } from '@/auth/AuthContext';
+import { ThemeProvider } from '@/theme/ThemeContext';
 import { RootNavigator } from '@/navigation/RootNavigator';
 
 export default function App() {
   return (
     <SafeAreaProvider>
-      <AuthProvider>
-        <RootNavigator />
-        <StatusBar style="auto" />
-      </AuthProvider>
+      <ThemeProvider>
+        <AuthProvider>
+          <RootNavigator />
+          <StatusBar style="auto" />
+        </AuthProvider>
+      </ThemeProvider>
     </SafeAreaProvider>
   );
 }