/sdd-implement-spec — implement a feature spec

You are operating within a Spec-Driven Development (SDD) workflow. See .claude/rules/sdd-constitution.md.

This skill takes one unprocessed feature spec (a specs/YYYY-MM-DD-<slug>/ directory whose ## Phase N — ... heading in specs/roadmap.md does not yet carry the ✅ lifecycle marker) and drives the work end-to-end: cuts the feature branch, walks plan.md task groups, runs the verification gates, commits atomically per group, runs a pre-push review (built-in /review plus three parallel deep-review subagents), pushes, opens a PR, and reports back on implementation, review, and verification.

The skill drives implementation — it is not merely scaffolding around it. The actual code changes happen in the main loop guided by plan.md. The spec itself is read-only.

Inputs

Argument in $ARGUMENTS (optional):

• empty → enumerate unprocessed specs and pick via AskUserQuestion
• integer (24, 25) → spec whose requirements.md H1 starts with # Phase <N>
• slug fragment ("gate-allowlist") → case-insensitive contains match against spec dir slugs (the portion after the date prefix); if ambiguous, list matches and ask
• relative path (specs/2026-05-21-gate-allowlist) → use directly; verify it exists and is a valid spec dir

Hard constraints