Extract independent MIT Mortar kit and contribution workflow

playwright.config.mjs

@@ -0,0 +1,17 @@
+import { defineConfig } from "@playwright/test";
+export default defineConfig({
+  testDir: "tests/browser",
+  workers: 4,
+  timeout: 30000,
+  use: {
+    baseURL: "http://127.0.0.1:4340",
+    launchOptions: process.env.UI_TEST_CHROME
+      ? { executablePath: process.env.UI_TEST_CHROME }
+      : {},
+  },
+  webServer: {
+    command: "npm run dev",
+    url: "http://127.0.0.1:4340",
+    reuseExistingServer: false,
+  },
+});