The red → green → refactor loop is anchored by leading words the model
already holds, so the step-by-step Workflow mostly restated the loop and
duplicated the horizontal-slicing anti-pattern. Drop the Workflow and
per-cycle checklist; fold their durable idea (vertical slices / tracer
bullets) into Anti-patterns and a short Rules-of-the-loop list.
Introduce **seam** as the leading word for where tests go, collapsing the
old Philosophy "public interfaces" prose and the Planning "confirm
interface / behaviors" handshake into one rule: test only at pre-agreed
seams, confirmed with the user before any test is written.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
