test(3d): npm run 3d:review — triptychs/heatmaps for ALL pairs, not just changed

compare-dirs gains --artifacts changed|always: 'always' also writes the
side-by-side triptych + heatmap for pairs that PASS the floor (blue-grey
UNCHANGED caption), so a human can eyeball old-vs-new without a failing
gate. The gating scripts keep the default (empty diff dir = green);
3d:review writes the full 47-pair set to output/diff/parity-review/.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/package.json

@@ -53,6 +53,7 @@
     "3d:check": "tsx tools/screenshots/compare-dirs.ts --old 3d-regression/baseline --new 3d-regression/output/native --out 3d-regression/output/diff/native-self --floors 3d-regression/floors.json --level native-self --label 3d-native --fail-on-change",
     "3d:check:webgl": "tsx tools/screenshots/compare-dirs.ts --old 3d-regression/baseline-webgl --new 3d-regression/output/webgl --out 3d-regression/output/diff/webgl-self --floors 3d-regression/floors.json --level webgl-self --label 3d-webgl --fail-on-change",
     "3d:check:parity": "tsx tools/screenshots/compare-dirs.ts --old 3d-regression/baseline --new 3d-regression/output/webgl --out 3d-regression/output/diff/parity --floors 3d-regression/floors.json --level webgl-vs-native --label 3d-parity",
+    "3d:review": "tsx tools/screenshots/compare-dirs.ts --old 3d-regression/baseline --new 3d-regression/output/webgl --out 3d-regression/output/diff/parity-review --floors 3d-regression/floors.json --level webgl-vs-native --label 3d-parity --artifacts always",
     "3d:test:webgl": "playwright test e2e/3d-webgl.spec.ts"
   },
   "devDependencies": {

tests/tools/screenshots/compare-dirs.ts

@@ -60,6 +60,7 @@ function parseArgs(argv: string[]): Record<string, string | boolean> {
         else if (a === '--floor') out.floor = argv[++i];
         else if (a === '--label') out.label = argv[++i];
         else if (a === '--fail-on-change') out.failOnChange = true;
+        else if (a === '--artifacts') out.artifacts = argv[++i];
         else {
             console.error(`[compare-dirs] unknown argument: ${a}`);
             process.exit(2);
@@ -72,7 +73,8 @@ function usageError(msg: string): never {
     console.error(`[compare-dirs] ${msg}`);
     console.error(
         '[compare-dirs] usage: --old <dir> --new <dir> --out <dir> ' +
-            '[--floors <json> --level <level>] [--floor <ratio>] [--fail-on-change] [--label <text>]'
+            '[--floors <json> --level <level>] [--floor <ratio>] [--fail-on-change] [--label <text>] ' +
+            '[--artifacts changed|always]'
     );
     process.exit(2);
 }
@@ -131,7 +133,12 @@ function main(): void {
         unchangedCount: 0,
     };
 
-    const caption = (status: 'added' | 'removed' | 'changed', name: string) => labelText(status, name, label);
+    const artifacts = (args.artifacts as string) || 'changed';
+    if (artifacts !== 'changed' && artifacts !== 'always')
+        usageError(`--artifacts must be "changed" or "always", got "${artifacts}"`);
+
+    const caption = (status: 'added' | 'removed' | 'changed' | 'unchanged', name: string) =>
+        labelText(status, name, label);
 
     for (const name of oldNames) {
         if (!newNames.has(name)) {
@@ -155,6 +162,16 @@ function main(): void {
         const { result, heatmap, triptych } = pair;
         if (result.verdict === 'unchanged') {
             report.unchangedCount++;
+
+            // Review mode: keep the triptych/heatmap for passing pairs too, so a
+            // human can eyeball old-vs-new side by side without a failing gate.
+            if (artifacts === 'always') {
+                const triptychPath = path.join(outDir, `${name}.triptych.png`);
+                savePng(triptychPath,
+                        withBottomLabel(triptych, caption('unchanged', name), LABEL.colors.unchanged));
+                savePng(path.join(outDir, `${name}.heatmap.png`), heatmap);
+            }
+
             continue;
         }
         const triptychPath = path.join(outDir, `${name}.triptych.png`);

tests/tools/screenshots/config.ts

@@ -103,10 +103,11 @@ export const LABEL = {
         added: [46, 125, 50] as [number, number, number], // green
         removed: [198, 40, 40] as [number, number, number], // red
         changed: [239, 108, 0] as [number, number, number], // orange
+        unchanged: [69, 90, 100] as [number, number, number], // blue-grey (review-only artifacts)
     },
 };
 
-export type LabelStatus = 'added' | 'removed' | 'changed';
+export type LabelStatus = 'added' | 'removed' | 'changed' | 'unchanged';
 
 /** Caption text: `CHANGED  name.png · kicad/pcbnew.spec.ts` (spec omitted if unknown). */
 export function labelText(status: LabelStatus, name: string, spec: string | null): string {