fix: let users with an unverified email log out

[jaspermayone]

Follow-up to #213.

Problem

logout ran behind authenticate_user!, which also requires a verified email. A signed-in user with an unverified email who clicked logout went to the email confirmation page and stayed signed in.

Change

AuthController skips authenticate_user! for logout and uses authenticate_user_without_email_verification! instead. A signed-out request to logout still goes to /login.

Tests

• New example in spec/requests/logout_spec.rb: a user with an unverified email logs out, and the user_sessions row is signed out. It fails without the fix.
• RSpec: 1048 examples, 0 failures. Minitest: 11 runs, 0 failures.
• bin/rubocop did not run: it crashes on main (prism / rubocop-ast).