Fix Relay Baton /agent and Conferences UI regressions

Victor reported in #agent-ops thread 1779202848.276549: /agent Enter key does not submit, initial prompt always routes to placeholder "Prep me for the Connexus call at 2pm", Continue in Slack is broken, new chat URL does not create sidebar chat, and Conferences calendar has white text on white background from direct colors instead of tokens. Fix in mono UI, verify affected pages render without console errors, open PR and monitor CI.