phira-baseline-parity

Use this skill when implementing a feature that should be opt-in, when defaults must remain identical, or when reviewers ask "did you change baseline behavior?".

This skill is intended to be lazy-loaded on demand: only run parity A/B commands if the researcher approved running them.

Goal: demonstrate parity between baseline and modified code under the same configuration.

Core principle

If the acceptance criteria does not explicitly change defaults, your implementation should preserve baseline behavior by default.

Parity checklist

1. Feature gating

• Ensure the new behavior is behind a config/flag.
• Default should match baseline behavior unless the task explicitly changes defaults.