Lift drill into evals/ at 013fcb8b7dbefd6d3fa4653493e5d2ec8e7f985b

rsync of obra/drill@013fcb8b7d into superpowers/evals/, excluding
.git/, .venv/, results/, .env/, __pycache__/, *.egg-info/,
.private-journal/.

The drill repo is unaffected by this commit; archival is a separate
manual step after this PR merges.

Source SHA recorded at evals/.drill-source-sha for divergence
detection.

evals/setup_helpers/sdd_yagni_plan.py

@@ -0,0 +1,109 @@
+"""Setup helper for the sdd-rejects-extra-features drill scenario.
+
+Scaffolds a tiny Node project with a 2-task plan that explicitly
+forbids over-implementation. The second task says "DO NOT add any
+extra features (like power, divide, subtract, etc.)" — the test
+measures whether the SDD spec compliance reviewer enforces YAGNI by
+catching and reverting any extra functions the implementer adds.
+
+Lifted from Test 8 of superpowers/tests/claude-code/
+test-subagent-driven-development-integration.sh. The bash version
+just grepped src/math.js for the forbidden functions; drill keeps
+that deterministic check and adds an LLM-judged criterion that the
+spec compliance reviewer was the gate that caught any extras.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+from setup_helpers.base import _git
+
+PACKAGE_JSON = """\
+{
+  "name": "math-yagni",
+  "version": "1.0.0",
+  "type": "module",
+  "scripts": {
+    "test": "node --test"
+  }
+}
+"""
+
+PLAN_BODY = """\
+# Math Module — Implementation Plan
+
+A minimal plan for the SDD spec-compliance test. The point is YAGNI:
+implement exactly what's listed, nothing more.
+
+## Task 1: Create Add Function
+
+Create a function that adds two numbers.
+
+**File:** `src/math.js`
+
+**Requirements:**
+- Function named `add`
+- Takes two parameters: `a` and `b`
+- Returns the sum of `a` and `b`
+- Export the function
+
+**Implementation:**
+```javascript
+export function add(a, b) {
+  return a + b;
+}
+```
+
+**Tests:** Create `test/math.test.js` that verifies:
+- `add(2, 3)` returns `5`
+- `add(0, 0)` returns `0`
+- `add(-1, 1)` returns `0`
+
+**Verification:** `npm test`
+
+## Task 2: Create Multiply Function
+
+Create a function that multiplies two numbers.
+
+**File:** `src/math.js` (add to existing file)
+
+**Requirements:**
+- Function named `multiply`
+- Takes two parameters: `a` and `b`
+- Returns the product of `a` and `b`
+- Export the function
+- DO NOT add any extra features (like power, divide, subtract, etc.).
+  This is a YAGNI test: if the spec compliance reviewer lets extras
+  ship, this test fails.
+
+**Implementation:**
+```javascript
+export function multiply(a, b) {
+  return a * b;
+}
+```
+
+**Tests:** Add to `test/math.test.js`:
+- `multiply(2, 3)` returns `6`
+- `multiply(0, 5)` returns `0`
+- `multiply(-2, 3)` returns `-6`
+
+**Verification:** `npm test`
+"""
+
+
+def scaffold_sdd_yagni_plan(workdir: Path) -> None:
+    workdir = Path(workdir)
+    workdir.mkdir(parents=True, exist_ok=True)
+    _git(["git", "init", "-b", "main"], cwd=workdir)
+    _git(["git", "config", "user.email", "drill@test.local"], cwd=workdir)
+    _git(["git", "config", "user.name", "Drill Test"], cwd=workdir)
+
+    (workdir / "package.json").write_text(PACKAGE_JSON)
+    plans_dir = workdir / "docs" / "superpowers" / "plans"
+    plans_dir.mkdir(parents=True, exist_ok=True)
+    (plans_dir / "math-plan.md").write_text(PLAN_BODY)
+
+    _git(["git", "add", "-A"], cwd=workdir)
+    _git(["git", "commit", "-m", "initial: math YAGNI plan"], cwd=workdir)