Refactor

A refactor changes structure, not behaviour. Bugs included: if you find one, note it for a separate fix and keep it as it is.

1. Pin the current behaviour

Find the tests that cover the code at its public interface: the command run through program.parseAsync(['node', 'td', ...]), or the exported helper. Where a behaviour has no test, add one that passes now, asserting what the code does today. Run them. Done when every behaviour you will touch has a passing test.

2. Delete dead code first

Remove code nothing reaches, if you can prove it: no caller (rg for every name, including the lazy command registry in src/index.ts and scripts/). Run the tests. Done when they pass.

3. Move one concept at a time

Make one structural change, run the pinned tests, repeat. Migrate every caller and delete the old API; no shims left behind. Command names, flags, --json output shapes and error codes are what people's scripts and agents rely on, and SKILL_CONTENT documents them: keep them, or stop and ask (changing them is a breaking feat!: release). Done when the tests pass after each step and no caller uses the old shape.

4. Leave the tests alone

Existing tests may change how they reach the code: import paths, names, call sites. They may not change their inputs or their assertions, including every expected output string. If an expected value changes, the behaviour changed: stop and say so.