writing-good-tests

Run `npx skills use "https://github.com/ed3dai/ed3d-plugins" --skill "ed3dai/ed3d-plugins/writing-good-tests"` and follow the generated skill instructions now. Read its complete output, redirecting it to a temporary file first if necessary. Resolve relative paths from the supporting-files directory it provides.

Use the skills in "https://github.com/ed3dai/ed3d-plugins" that are relevant to the current task. Run `npx skills add "https://github.com/ed3dai/ed3d-plugins"` and select the relevant skills, then follow their instructions.