Serves the post-PR-#3 dist/ on a loopback port with EA2/auth routes
stubbed at the HTTP level, then runs the user journey:
PASS login_renders
PASS login_shows_three_personas (Mariana CEO, Aisha HR, Rohan IT)
PASS login_has_sso_button
PASS persona_click_signs_in_and_leaves_login
PASS no_error_dump_on_login
Closes the open dogfood failure 'ceo_persona_dev_login_lands_on_landing'
in source. Cluster fix is still required to make this happen on the
live URL — tracked in FM06/flowmaster-ops#1176.
