Refactor AuthContext into smaller files

Refactors the AuthContext.tsx file into smaller, more manageable files to improve code organization and maintainability. The functionality remains the same.

src/pages/Settings.tsx

@@ -1,11 +1,10 @@
-
 import React from 'react';
 import { useNavigate } from 'react-router-dom';
 import NavBar from '@/components/NavBar';
 import SyncSettings from '@/components/SyncSettings';
 import { User, CreditCard, Bell, Lock, HelpCircle, LogOut, ChevronRight } from 'lucide-react';
 import { cn } from '@/lib/utils';
-import { useAuth } from '@/contexts/AuthContext';
+import { useAuth } from '@/contexts/auth';
 
 const SettingsOption = ({
   icon: Icon,