Gated RED/GREEN/commit loop for a single broken-down task. Use when picking up any build task from a delivery plan or issue - whether the repo has a test runner or only a deterministic verification script. Every increment lands verified, smallest-first, with a commit trail a reviewer can replay. Trigger phrases: "build this task", "implement this story", "work on this issue", "pick up this task", "start building", "implement the slice".
