test: harden exhaustive compatibility suites

app/game-frontend/e2e/board.spec.ts

@@ -4,7 +4,11 @@ import { dirname, resolve } from 'node:path';
 import { fileURLToPath } from 'node:url';
 
 const repositoryRoot = resolve(dirname(fileURLToPath(import.meta.url)), '../../..');
-const imageRoots = [resolve(repositoryRoot, '../image'), resolve(repositoryRoot, '../../image')];
+const imageRoots = [
+    ...(process.env.FRONTEND_PARITY_IMAGE_ROOT ? [resolve(process.env.FRONTEND_PARITY_IMAGE_ROOT)] : []),
+    resolve(repositoryRoot, '../image'),
+    resolve(repositoryRoot, '../../image'),
+];
 const artifactRoot = process.env.BOARD_ARTIFACT_DIR;
 
 type Article = {