This commit introduces optional `first_name` and `last_name` fields to the user model, including database migrations, backend, and frontend support. It enhances user profiles, updates user creation and editing flows, and refines the UI to display full names where available.
Introduced a backend API endpoint for changing user passwords with validation. Added a new "User Settings" page in the frontend to allow users to update their passwords, including a matching UI update for navigation and styles.
