Implement Logout route

[lululeon]

For now, we will handle basic signup with username and password only. This ticket will leverage the lucia auth middleware to receive and process a logout request

Refs: https://v2.lucia-auth.com/guidebook/sign-in-with-username-and-password/

Acceptance criteria

• refactor / complete implementation of the auth/logout route so that logout succeeds
• previous token is no longer usable to access api
• tests added