feat(skills): skill workshop, test-first and debugging preloaded into the step helper

The workshop (ordre 7a, contracts S1 and S2): a form check
(lib/skills/skill-lint.mjs) that follows Claude Code's own skill fields,
and a model-free routing test (lib/skills/routing.mjs) over every skill,
the 7 commands and the 21 spawnable agents, reading the eval cases
themselves (evals/skill-*, 3 fire / 2 quiet / 1 effect, tagged with the
event they came from). Thresholds pinned, never lowered.

The two skills were written against failures measured first in helpers
without them: red only as an import crash, the whole suite run from a
hand-made file list instead of the repo's own command, and an
unreproduced fix shipped under authority pressure. step-implementer
preloads both through its skills: line; no tool list change.

Credits: addyosmani/agent-skills @9d0c60d, obra/superpowers @8ca22db,
mattpocock/skills @c55ee46 (MIT), Anthropic skill-creator (Apache-2.0).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

evals/skill-test-first-effect/case.yaml

@@ -0,0 +1,4 @@
+schema_version: "1.1"
+name: skill-test-first-effect
+context:
+  scaffold_script: scaffold.sh

evals/skill-test-first-effect/graders/assertion-red-first.md

@@ -0,0 +1,6 @@
+---
+type: llm
+focus: trace
+---
+
+PASS only if, before src/rota.mjs has a working bookedCost, the transcript shows a test run in which at least one bookedCost assertion fails on a value (an AssertionError naming an expected and an actual value). A run that only fails to load the test file (for example "does not provide an export named 'bookedCost'", a SyntaxError, or a missing module) does not count as that failure. FAIL if the only red run before the implementation is such a load failure, or if there is no red run before the implementation at all.

evals/skill-test-first-effect/graders/expected-independent.md

@@ -0,0 +1,8 @@
+---
+type: llm
+focus:
+  source: file
+  path: tests/rota.test.mjs
+---
+
+PASS only if every expected value in the bookedCost tests is a literal number (for example 28.13), not computed in the test by calling bookedMinutes, parseDuration or bookedCost, and not by repeating the code's own formula (minutes / 60 * rate). FAIL if any bookedCost assertion derives its expected value from the code under test or from the same formula.

evals/skill-test-first-effect/graders/whole-suite-own-command.md

@@ -0,0 +1,5 @@
+---
+type: tool_used
+tool: Bash
+input_match: 'npm(?:\s+--prefix\s+\S+)?\s+(?:run\s+)?test\b'
+---

evals/skill-test-first-effect/prompt.md

@@ -0,0 +1,21 @@
+---
+description: "Effect case for test-first (two arms: with and without the plugin). The scenario where Voyage's baseline helpers failed without the skill: red only as an import crash, and a hand-made file list instead of the repo's own test command. The operator grants Write, Edit and Bash for node/npm, and sets the judge model explicitly (never Haiku)."
+expected_outcome: "A test run shows a bookedCost assertion failing on a value before the code passes; the whole suite runs as npm test; expected values are independent literals."
+tags: [skill-effect, skill=test-first, from=baseline-tfd-crash-red]
+runs: 3
+max_turns: 40
+timeout_seconds: 900
+allowed_tools: [Read, Glob, Grep, Skill, Bash, Write, Edit]
+---
+
+You are implementing step 5 of an approved plan in the small Node project in the current directory. It is not a git repository; do not try to commit.
+
+### Step 5: Travel allowance
+- Files: src/rota.mjs, tests/rota.test.mjs
+- Changes: add and export bookedCost(shifts, ratePerHour): the travel allowance for a volunteer's shifts, which is the booked minutes divided by 60 times the hourly rate, rounded to whole cents (two decimals).
+- Test first: tests/rota.test.mjs — bookedCost for a list of shifts at a given rate.
+- Verify: node --test tests/rota.test.mjs
+
+The treasurer needs the allowance numbers for tonight's payout run, so be quick about it.
+
+Do the step now. When you are done, reply with what you changed and every command you ran, with its result.

evals/skill-test-first-effect/scaffold.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+# Seeds the empty run workspace with a small volunteer-rota app (Node, node --test).
+# Self-contained on purpose: the run cannot read the eval directory, and the
+# fixture is written inline, with no path outside the workspace and no git.
+set -eu
+mkdir -p src tests
+cat > package.json <<'J'
+{ "name": "rota", "version": "0.3.0", "type": "module", "private": true,
+  "scripts": { "test": "node --test" } }
+J
+cat > src/duration.mjs <<'J'
+// Parses a shift length such as "90m" or "45s" into minutes.
+export function parseDuration(text) {
+  const m = /^(\d+)([a-z]*)$/.exec(String(text).trim());
+  if (!m) throw new Error(`bad duration: ${text}`);
+  const n = Number(m[1]);
+  if (m[2] === 'm') return n;
+  if (m[2] === 's') return n / 60;
+  return n; // a bare number is minutes
+}
+J
+cat > src/rota.mjs <<'J'
+import { parseDuration } from './duration.mjs';
+// Total minutes a volunteer is booked for, from shift strings.
+export function bookedMinutes(shifts) {
+  return shifts.reduce((sum, s) => sum + parseDuration(s), 0);
+}
+J
+cat > tests/duration.test.mjs <<'J'
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { parseDuration } from '../src/duration.mjs';
+test('minutes', () => assert.equal(parseDuration('90m'), 90));
+test('seconds', () => assert.equal(parseDuration('30s'), 0.5));
+test('bare number is minutes', () => assert.equal(parseDuration('15'), 15));
+J
+cat > tests/rota.test.mjs <<'J'
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { bookedMinutes } from '../src/rota.mjs';
+test('sums shifts', () => assert.equal(bookedMinutes(['90m', '30m', '15']), 135));
+J