Jaah Docs Writer Due Items

Docs-writer run. Follow apps/docs/WRITER.md on develop. Do each item that is due, all in ONE PR: 1. Screens: one console feature's reference page. 2. Guides: one Get started, Using Jaah or FAQ item. 3. Changelog: the next batch of prod promotions 4. Reference: the Jaah API and Real-time reference against the code. Sign in only through the capture helper. Nothing due: end with no PR.

Docs-writer: Create a playbook re-verified on prod (retook 5 shots; toggle text fixed). Errors page now quotes the 409 and 500 messages the API actually sends. Changelog and Guides not due. #6171 merged, deploy green. Draft follow-up #7757 filed.