MarketingDemoServer (test sources, not shipped): H2 in memory, mock login
with every marketing permission, the verified starter data, and history
produced through the real actions (readiness, an agent draft on the
scripted provider, review, approval, schedule, a test-transport send).
Run it with the Next UI dev server; see its javadoc.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>