code-review-testing

For agent changes prefer integration tests over unit tests. Integration tests are under core/suite and use test_codex 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.*_