Two unit tests for run_hermes_oauth_login_pure():
1. test_authorization_url_state_is_not_pkce_verifier — asserts state in the
auth URL is independent from the PKCE code_verifier sent in the token
exchange, and that the verifier never appears in the URL.
2. test_callback_state_mismatch_aborts — asserts the flow returns None
(no token exchange) when the callback state does not match the value
we generated.
Negative control verified: reintroducing the b17e5c10 vulnerable pattern
(state = verifier, no callback validation) makes both tests fail.
Also adds AUTHOR_MAP entry for shaun0927 (contributor of the fix).