implement — turn the task list into tested code

You have a spec, a plan, and an ordered task list (from specify → plan → tasks), and the analyze gate has cleared. This skill does the building: it walks the tasks in order, writes each one test-first, stops to show its work after every task, and records the decisions it makes along the way. It is the intent → shipped code engine's hands — verify is the gate that comes after, not part of this skill.

This is a process skill. It owns the discipline (red → green → refactor, checkpoints, decision logging, constitution adherence). It does not own the test tooling — pytest fixtures, go test table-drivers, Vitest/Playwright, flutter test — those belong to the stack skill, and you call into them rather than reinventing them.

Before you write a line of code

Run this short gate. Skipping it is the most common way an implement session goes sideways. This gate is a hard refuse, not a checklist to feel good about: if it fails you stop and route back — you do not write feature code anyway.