Refactor authentication and theme context usage

- Moved authentication hooks and context to a dedicated hooks directory.
- Updated imports in various components and pages to use the new hooks.
- Created AuthContext and ThemeContext for better state management.
- Refactored ThemeProvider to utilize the new ThemeContext.
- Cleaned up sidebar and button components for consistency and readability.
- Ensured all components are using the latest context and hooks for authentication and theme management.

src/components/sidebar/AppSidebar.tsx

@@ -8,7 +8,7 @@ import {
   SidebarMenuItem,
   useSidebar,
 } from '@/components/ui/sidebar'
-import { useAuth } from '@/contexts/AuthContext'
+import { useAuth } from '@/hooks/use-auth'
 import { Activity, Home, Users } from 'lucide-react'
 import { Link, useLocation } from 'react-router'
 import { NavUser } from './NavUser'