Restore backend state when Playwright test finishes (#1168)

* Restore backend state when Playwright test finishes. Resolve #1094

* Add warning when env var not set

* Rename and replace with scaffolding option for models dir

* Rename

* Define another env var [skip ci]

* Fix paths [skip ci]

* Update README.md

---------

Co-authored-by: Chenlei Hu <huchenlei@proton.me>

browser_tests/globalSetup.ts

@@ -0,0 +1,20 @@
+import { FullConfig } from '@playwright/test'
+import { backupPath } from './utils/backupUtils'
+import dotenv from 'dotenv'
+
+dotenv.config()
+
+export default function globalSetup(config: FullConfig) {
+  if (!process.env.CI) {
+    if (process.env.TEST_COMFYUI_DIR) {
+      backupPath([process.env.TEST_COMFYUI_DIR, 'user'])
+      backupPath([process.env.TEST_COMFYUI_DIR, 'models'], {
+        renameAndReplaceWithScaffolding: true
+      })
+    } else {
+      console.warn(
+        'Set TEST_COMFYUI_DIR in .env to prevent user data (settings, workflows, etc.) from being overwritten'
+      )
+    }
+  }
+}