User landing page

[Ayushpatel2026]

Currently, existing users are redirected to the register page, which gives them the ability to register more than one patient per user.
Existing users should be redirected to landing page, where they can view their appointments, schedule new ones etc... (using the reusable DataTable, and AppointmentForm components)
They should also be able to update their profile information (using the reusable RegisterForm component)