test(e2e): add playwright e2e harness

Process and API-only Playwright harness: binary and image setup, server/CLI runners, fake Docker Engine socket, read-only database inspection, secret redaction in reports, seeded fuzzing, leak detection and harness self-checks.

e2e/setup/image.setup.ts

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+// Copyright (C) 2026 Bryan Joshua Pedini
+
+/**
+ * `image-setup` project: check the image under test ($DPSAPI_IMAGE) and the tools the image
+ * suite needs. All image tests depend on it.
+ */
+import { test as setup } from '@playwright/test';
+import { imageRef } from '../harness/env';
+import { HarnessError } from '../harness/errors';
+import { requireCurl, requireDocker, sh } from './prereq';
+
+setup('image prerequisites: Docker, curl, image under test', async () => {
+  requireCurl();
+  requireDocker();
+  const image = imageRef();
+  if (!image) throw new HarnessError('prerequisite', 'DPSAPI_IMAGE is not set (run `make docker-e2e`, or export DPSAPI_IMAGE=<image ref>)');
+  const r = sh('docker', ['image', 'inspect', '--format', '{{.Id}}', image]);
+  if (r.code !== 0) throw new HarnessError('prerequisite', `image ${image} is not present locally (build it with \`make docker\`): ${r.err.trim()}`);
+});