Add OPNsense WebGUI regression tests

tests/ui/playwright.config.js

@@ -0,0 +1,18 @@
+const { defineConfig } = require('@playwright/test');
+
+const baseURL = process.env.OPNSENSE_UI_BASE_URL;
+
+if (!baseURL) {
+  throw new Error('Set OPNSENSE_UI_BASE_URL to the disposable OPNsense WebGUI URL.');
+}
+
+module.exports = defineConfig({
+  testDir: './specs',
+  timeout: 30000,
+  workers: 1,
+  use: {
+    baseURL,
+    ignoreHTTPSErrors: true,
+    trace: 'retain-on-failure',
+  },
+});