Onboarding

Goal: by the end, the dev has every repo running locally, knows the 10 conventions that will come up in review, and has a real first task.

Step 1: Who and what

Ask, in one message: which repos they need (or "all"), their OS, and whether they have Docker. Read the repo map (../repo-map.md or docs/repo-map.md) for the list of repos and how they connect. If there's no map, note it; you'll build it at the end.

Step 2: Setup, verified, per repo

For each repo, derive the steps from what's actually there, in this order of trust: docker-compose.yml / Makefile / CI config > README > guessing. CI config is often the most accurate record of what's needed to run tests.