duet-agent: Skill for Claude Code

Implement Spec

Build the active spec to completion, one reviewable pass at a time. The spec is the implementation plan; user constraints and accepted experimental evidence remain binding when the architecture changes.

A pass (usually one slice) is a commit checkpoint, not a stopping point. The job is the whole spec — every slice, every global TODO — not the first green commit. Finishing a pass means starting the next one, not handing back to the user. Only stop when the spec is fully implemented (or a genuine blocker needs a decision only the user can make).

Work in parallel wherever the graph allows. Do not walk the ladder one slice at a time when slices are independent. Read the spec's dependency graph as a wavefront and delegate independent passes to subagents that run concurrently (see Rules) — you orchestrate and integrate; only serialize what genuinely depends on prior work.

Workflow

1. Read the repo README, the spec README, and the next slice before editing. Load any skills named by the spec. Identify the current pickup point, global TODOs, required gates, and what must stay green. If a multi-slice spec lacks a live handoff prompt, add one before the first pass ends. For a validated spike, apply Preserve the winner below before editing.
2. Reconcile the plan with the current code. If the slice would preserve a development-only shim, duplicated type, weak wrapper, or obsolete path, replace it with the simpler architecture and update the spec handoff.
3. Implement one coherent pass: usually one slice, one vertical checkpoint, or one architecture correction. Keep the review surface small enough to audit.
4. Verify the actual contract. For behavior changes, run the focused tests first; for browser-visible work, use the real browser/harness and inspect screenshots so the subject is framed and readable, not merely nonblank. A visual CHANGE carries two extra proofs before you claim it: a byte/pixel diff against the pre-change baseline on the production route (static checks and re-anchored assertions all pass on a no-op — a palette pass once shipped "verified" while the production frame was byte-identical), and an unprimed screenshot-critique — at the user's reported framing when the pass answers their visual bug report — before declaring it fixed; the implementer's eyes are primed by the fix and repeatedly pass what fresh eyes catch. Never weaken an existing default gate or repin a failing contract without proving the old contract is wrong.
5. Review the change list and clean up after every pass, before committing. Read git status/git diff --stat line by line and account for every path: one-off probes, shot scripts, scratch files, nohup.out, ad-hoc screenshot dirs, and disposable SPIKE/debug notes never enter a commit — scratch stays out of the tree. Preserve frozen references, fixtures, and research evidence in the project's reference or spec assets area. A file without a durable purpose does not ship. Delegated agents leak these; the integrating reviewer re-checks the merged tree with the same eye.