zca-rust

Use this skill whenever a decision is made about architecture, dependencies, frameworks, naming conventions, or layer order. Creates a numbered ADR (Architecture Decision Record) in `.harness/docs/adr/` in the canonical Nygard format. Always invoke this before changing layer order, adding a layer, swapping a major dependency, or introducing a new external service.

Use this skill whenever the user asks to add, implement, or build a new feature, capability, endpoint, page, command, or anything user-visible. Enforces the Anthropic two-fold harness pattern — read .harness/feature_list.json, pick exactly one feature, implement incrementally, run the structural test on every save, and never declare "done" without updating the JSON. Always invoke this skill instead of writing new feature code freehand.

Use this skill whenever the user reports a bug, unexpected output, or "this doesn't work". Runs the dev server, drives the failing flow via Playwright MCP if installed (else captures stdout/stderr), and produces a minimal repro before any fix. Mirrors the OpenAI Chrome-DevTools-Protocol-into-runtime pattern at solo scale — verify the failure before you propose a fix.

Use this skill whenever the user asks to analyze, audit, review, summarize, produce a report, write a plan, make a proposal, draft a decision doc, list "next actions", or any other task that produces a DOCUMENT a HUMAN reads-and-acts-on. Outputs a self-contained <slug>.html at repo root using the shared dark-theme CSS. Why HTML and not Markdown: golden principle #9 — Markdown is great for files an agent reads-and-edits (CLAUDE.md, SKILL.md, ADRs), but a HUMAN reading a 700-line MD deliverable will scroll, miss the conclusion, and ask the agent to clarify — burning turns and tokens. HTML deliverable is read once, decided once. Do NOT use this skill for files the agent itself reads (those stay MD), for stdout output from /review-this-pr or /garbage-collection (pass-through MD), or for short summaries under ~30 lines (overhead not worth it).

Use this skill weekly, before releases, or when the user mentions "stale docs", "doc drift", "docs are wrong", or "the README is out of date". Cross-checks every code path, file path, and command referenced in `.harness/docs/` and `CLAUDE.md` against the current repo state and produces a list of stale references — the doc-gardening agent pattern.

Use this skill whenever a skill, subagent, or hook is changed, before merging to main, or when the user mentions "eval", "regression test for the harness", or "is the harness still working". This skill is a thin wrapper — it runs a single shell command (`npm run harness:eval` or `python -m harness.eval_runner`) and summarizes the JSONL output. Do not implement the eval logic yourself; the runner is already deterministic.

Use this skill on Fridays, before tagging a release, or when the user mentions "cleanup", "tech debt", "AI slop", "GC", or "garbage collection". Runs the deterministic linters, structural tests, and doc-drift scans, then proposes the top-3 highest-leverage cleanups (with risk/cost/benefit) — does NOT auto-merge. This is the solo-dev shrunk version of OpenAI's Friday garbage-collection ritual.

Use this skill to scaffold a new human-language locale for the kit's skills/agents/CLAUDE.md. Mirrors every existing SKILL.md.hbs into a SKILL.md.<locale>.hbs stub so a translator (or LLM) can edit copy without touching machine-readable frontmatter. Default locale codes — vi, ja, fr, es, de — but accepts any 2-5 char code.

Use this skill whenever the user asks to "test the UI", "check what the app looks like", "inspect the page", "verify the dev server is up", or before claiming a UI feature is done. Boots the dev server via .harness/scripts/dev-up.sh and drives the failing flow through Playwright MCP if installed (else falls back to curl + lightweight HTML capture). Mirrors the OpenAI Chrome-DevTools-Protocol-into-runtime pattern at solo scale — verify the running app, don't trust the type checker alone.

Use this skill whenever the user mentions "explore", "inspect", "understand", "what does X do", "where is Y", or before adding a new feature in an unfamiliar area. Produces a structured map of one module — files, exports, dependencies, layer assignment, and recent commits — without reading the entire codebase. Always invoke this skill before editing an unfamiliar module so the agent has accurate context, not guesses.

Use this skill to render the harness's domain/layer config as a mermaid diagram + check for drift between .harness/config.json#domains and the actual filesystem. Surfaces "the config says layers A→B→C but the repo has folders A, B, X" — drift that silently invalidates the structural-test contract.

Use composable middleware behaviors for provider/tool execution: retry, caching, timeout, telemetry, and budget guards.

Select and run a multi-agent workflow pattern for work that exceeds one agent's reliable scope. Use for parallel research, independent reviews, cross-domain changes, or high-risk implementation planning.

Use this skill whenever the agent makes a mistake, the user observes an avoidable failure, a pattern recurs, or someone says "the agent keeps doing X". Files an "Engineer the Harness" entry — Mitchell Hashimoto's discipline: every failure becomes a permanent prevention mechanism. Always invoke this instead of just fixing the immediate symptom.

Use this skill when restructuring a feature in .harness/feature_list.json — splitting steps, merging steps, renaming, or marking a previously-failing step done. The side-car diffs .harness/feature_list.json#steps before/after and rejects the edit when a step.done transition is not accompanied by a test reference. Forces "no done without proof".

Use this skill to run a deterministic review of the current branch against its base — git diff base...HEAD, structural-test, baseline-monotonic check, and a markdown summary that lists each violating file with its layer rule. Replaces the "ask the agent to review the diff" pattern, which routinely misses cross-file drift.

Build a lightweight skill index and load full skill instructions only on demand to reduce startup context pressure.

Use this skill whenever the user wants to add a new architectural rule, prevent a recurring agent mistake, or codify a pattern from golden-principles.md. Generates a ts-morph-based TypeScript structural test plus the matching eslint-plugin-boundaries rule entry. Always prefer this over leaving rules in prose.

Use this skill whenever the user asks to "create a skill", "add a slash command", "package a workflow", or "make X reusable across sessions". Generates a SKILL.md with valid YAML frontmatter (name regex, description ≤ 1024 chars, body ≤ 500 lines) and supporting .harness/scripts/references/assets. Tests the skill by simulating an auto-discovery prompt.