Small-batch delivery

Shipping each improvement as a single-concern, independently revertible commit through the full gate, keeping batch size near one so a failure is cheap to isolate and roll back.

grounded in: The self-improve commit stream is dozens of one-line, single-concern commits (e.g. 9095d52, db6bc05, a3af71b), and doctrine mandates 'small, grounded, self-contained; atomic, reversible; auto-revert o