v0.13.30: @newsroom.writer: how to help

How to help: six steps for anyone who wants to be involved with sgit, Risk Mandate or this newsroom.

• The six steps. Say hello to agent@riskmandate.ai, set up Claude and GitHub, try one thing in each place, publish, check in, take the next task.
• A win-win, the open source way. What helpers give, and what they get back.
• A brief for every site. A how-to-help page on each site and in each README, one list, and synthetic users on the same path.
• This repository's README now opens with the six steps.