feat: add settings page with user info and logout

[devZenta]

This pull request introduces a new user account settings page and improves authentication flow and user navigation. The main updates include adding a protected route for the homepage, implementing a settings page with user info and sign-out functionality, and updating navigation logic after login and signup. Additionally, UI enhancements have been made for the header and settings page.

Authentication & Routing Improvements

• Added a ProtectedRoute component to restrict access to the homepage (/) for authenticated users only. Unauthenticated users are redirected to the login page. (src/components/ProtectedRoute.tsx, src/App.tsx) [1] [2]
• Introduced a new /settings route and page, displaying user info and providing a sign-out button. The page handles loading and unauthenticated states gracefully. (src/pages/Settings/page.tsx, src/App.tsx) [1] [2]
• Updated navigation after successful login and signup to use window.location.href instead of React Router's navigate, ensuring a full page reload and session update. (src/pages/Login/page.tsx, src/pages/Signup/page.tsx) [1] [2]

UI Enhancements

• Added a user icon to the header that links to the new settings page, with improved styling for hover effects and responsiveness. (src/components/Header.tsx, src/components/Header.css) [1] [2]
• Implemented a dedicated stylesheet for the settings page, providing a visually appealing layout for user info and actions. (src/pages/Settings/Settings.css)

Other Updates

• Changed the local development API base URL in the auth client to match the frontend port. (src/lib/auth-client.ts)
• Removed unused imports and navigation hooks in login and signup pages for cleaner code. (src/pages/Login/page.tsx, src/pages/Signup/page.tsx) [1] [2] [3] [4]