Implement dark theme and comprehensive profile settings with working functionality

frontend/App.tsx

@@ -1,40 +1,12 @@
 import React from 'react';
 import { StatusBar } from 'expo-status-bar';
 import { ApolloProvider } from '@apollo/client';
-import { Provider as PaperProvider, MD3DarkTheme, configureFonts } from 'react-native-paper';
+import { Provider as PaperProvider } from 'react-native-paper';
 import { SafeAreaProvider } from 'react-native-safe-area-context';
 import { apolloClient } from './src/services/apollo-client';
 import { AuthProvider } from './src/contexts/AuthContext';
 import { AppNavigator } from './src/navigation/AppNavigator';
-
-// Кастомная темная тема в черно-фиолетовых тонах
-const theme = {
-  ...MD3DarkTheme,
-  colors: {
-    ...MD3DarkTheme.colors,
-    primary: '#9333ea',
-    secondary: '#a855f7',
-    tertiary: '#7c3aed',
-    background: '#0a0a0f',
-    surface: '#1a1a2e',
-    surfaceVariant: '#2d2d42',
-    onSurface: '#ffffff',
-    onSurfaceVariant: '#e5e5e7',
-    onPrimary: '#ffffff',
-    elevation: {
-      level0: 'transparent',
-      level1: '#1a1a2e',
-      level2: '#2d2d42',
-      level3: '#3d3d56',
-      level4: '#4d4d6a',
-      level5: '#5d5d7e',
-    },
-    outline: '#7c3aed',
-    outlineVariant: '#6d28d9',
-    error: '#ef4444',
-  },
-  roundness: 12,
-};
+import { theme } from './src/theme';
 
 export default function App() {
   return (