feat: Playwright against deployed music-room (shell + optional unionid chain)

No Rust/Compose; GitHub Actions with MOICEN_E2E_UNIONID secret; dotenv .env.e2e; proxy install script.

Made-with: Cursor

package.json

@@ -0,0 +1,12 @@
+{
+  "name": "huike-e2e-moicen",
+  "private": true,
+  "scripts": {
+    "test": "playwright test",
+    "install:with-proxy": "bash scripts/install-with-proxy.sh"
+  },
+  "devDependencies": {
+    "@playwright/test": "^1.49.0",
+    "dotenv": "^16.4.5"
+  }
+}