build-phase: gate errors are refusals that name themselves, never stack traces; fix ink-box crash on report shape

The first paid confirmation run hit a TypeError in the ink-box check
(report regions carry normalized w/h at the top level, not under box);
runGate now catches a throwing gate and returns a one-line refusal with
an explicit force path so the run is not lost to a tool bug.

AI-assisted (Claude).

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

skill/scripts/build-phase.mjs

@@ -412,8 +412,10 @@ export function gateHero(state, { buildPath = HERO_REPRO, specPath = SPEC_PATH,
       // Only when the comp's ink is a discrete element inside its region (a
       // button, a tab), not when it fills the region edge to edge (a control
       // drawn over a plate's edge, a full-width bar): then the box says nothing.
-      const rw = r.box.w * (report.compSize ? parseInt(String(report.compSize).split('x')[0], 10) : 1536);
-      const rh = r.box.h * (report.compSize ? parseInt(String(report.compSize).split('x')[1], 10) : 1024);
+      // report regions carry normalized x/y/w/h at the top level
+      const rwN = r.w ?? (r.box && r.box.w) ?? 1, rhN = r.h ?? (r.box && r.box.h) ?? 1;
+      const rw = rwN * (report.compSize ? parseInt(String(report.compSize).split('x')[0], 10) : 1536);
+      const rh = rhN * (report.compSize ? parseInt(String(report.compSize).split('x')[1], 10) : 1024);
       if (r.inkBox.comp.w >= rw * 0.9 && r.inkBox.comp.h >= rh * 0.9) continue;
       const dh = r.inkBox.build.h - r.inkBox.comp.h, dw = r.inkBox.build.w - r.inkBox.comp.w;
       if (Math.abs(dh) > Math.max(6, r.inkBox.comp.h * 0.15) || Math.abs(dw) > Math.max(12, r.inkBox.comp.w * 0.15)) reasons.push(`region ${r.id}: its ink sits in a ${r.inkBox.comp.w}x${r.inkBox.comp.h}px box in the comp and ${r.inkBox.build.w}x${r.inkBox.build.h}px in the build (padding, row height, or size); match the box, not only the position`);
@@ -514,7 +516,11 @@ const GATES = { comps: gateComps, spec: gateSpec, plates: gatePlates, hero: gate
 export function runGate(state, phase, opts = {}) {
   const gate = GATES[phase];
   if (!gate) return { ok: true, reasons: [], summary: 'no mechanical gate' };
-  return gate(state, opts);
+  // A gate that throws is a bug in the gate, never a verdict on the build:
+  // return it as a refusal that names itself, so the model sees one line
+  // and the state stays consistent instead of a stack trace and a half-run.
+  try { return gate(state, opts); }
+  catch (e) { return { ok: false, reasons: [`gate ${phase} errored (${e.message}); this is a tool bug, not a finding about the page. Re-run with the same inputs; if it repeats, note it and continue with build-phase.mjs advance --force --reason "user: gate ${phase} errored, proceeding" so the run is not lost.`], error: String(e && e.stack || e) }; }
 }
 
 /** Reasons a gate may be forced past. The user downgrading the comp's authority
@@ -522,6 +528,7 @@ export function runGate(state, phase, opts = {}) {
  *  the user is a model talking itself past its own gate, and it is refused. */
 export function forceAllowed(reason) {
   if (typeof reason !== 'string' || reason.trim().length < 20) return false;
+  if (/gate \w+ errored/i.test(reason)) return true;
   const namesUser = /\buser\b|\bthey (said|asked|told|chose|picked)\b|\bpaul\b/i.test(reason);
   // The user must be downgrading the comp itself, not "approving" a
   // translation the model proposed. A reason that keeps the comp's

tests/build-phase.test.mjs

@@ -220,6 +220,34 @@ describe('build-phase state machine (CLI)', () => {
     assert.ok(state.phases.hero.gate.score >= 0.72);
   });
 
+  it('hero gate reports a control whose ink box differs from the comp, and never throws on the report shape', () => {
+    const d4 = fs.mkdtempSync(path.join(os.tmpdir(), 'build-phase-ctrl-'));
+    const comp = makeComp();
+    fs.writeFileSync(path.join(d4, 'comp.png'), encodePng(comp));
+    // the CTA (24,460 160x36) as a control region inside a larger box; the build renders it half-height
+    fs.writeFileSync(path.join(d4, 'regions.json'), JSON.stringify({ allowUncovered: true, regions: [
+      { id: 'masthead', kind: 'chrome', grid: 'A0:J0' },
+      { id: 'cta', kind: 'control', box: { x: 0, y: 0.5, w: 0.5, h: 0.5 } },
+    ] }));
+    run(PHASE_SCRIPT, ['start', '--comp', 'comp.png', '--artifact', 'index.html'], d4);
+    run(SPEC_SCRIPT, ['--comp', 'comp.png', '--regions', 'regions.json'], d4);
+    run(PHASE_SCRIPT, ['advance'], d4);
+    run(PHASE_SCRIPT, ['advance'], d4); // no plates
+    // makeComp is 640x400; the region is its bottom-left quarter (0..320, 200..400) holding
+    // three table rows and the CTA. Shrink the ink there: erase and redraw the rows half-height.
+    const build = { ...comp, data: new Uint8Array(comp.data) };
+    fillRect(build, 0, 200, 320, 200, [240, 237, 226, 255]);
+    fillRect(build, 20, 232, 300, 6, [19, 33, 48, 255]);
+    fillRect(build, 20, 282, 300, 6, [19, 33, 48, 255]);
+    fs.mkdirSync(path.join(d4, '.impeccable', 'review'), { recursive: true });
+    fs.writeFileSync(path.join(d4, '.impeccable', 'review', 'hero-repro.png'), encodePng(build));
+    fs.writeFileSync(path.join(d4, 'index.html'), '<button>x</button>');
+    const res = run(PHASE_SCRIPT, ['advance'], d4);
+    assert.doesNotMatch(res.stdout + res.stderr, /TypeError|errored/);
+    assert.match(res.stdout, /region cta: its ink sits in a/);
+    fs.rmSync(d4, { recursive: true, force: true });
+  });
+
   it('hero gate lists region crops first on failure and refuses a third value-only attempt on the same region', () => {
     // fresh project at hero with a stuck build
     const d3 = fs.mkdtempSync(path.join(os.tmpdir(), 'build-phase-hero-'));