code-review-testing

From README

For agent changes prefer integration tests over unit tests. Integration tests are under core/suite and use testcodex to set up a test instance of codex. Features that change the agent logic MUST add an integration test: Provide a list of major logic changes and user-facing behaviors that need to be tested. If unit tests are needed, put them in a dedicated test file (tests.rs). Avoid test-only functions in the main implementation. Check whether there are existing helpers to make tests more streamlined and readable.