clankership/plugin

Set up testing

1. Call get_agent_instructions with kind: "fixtures", then with kind: "test-ci", and the team's key.
2. Follow the fixtures guidance to build the Fixture API, set each deployment's fixture URL, and write TESTING.md from its template.
3. Follow the test-ci guidance to add the CI runs.
4. Run clanker fixtures check --environment <env> for every environment until it passes. Stop where the instructions say to wait for approval.
5. When the person asks to change how testing is set up, save it with update_agent_instructions.