fix: add pnpm

Author: holtwick

package.json

@@ -79,6 +79,7 @@
     "esbuild": "^0.25.2",
     "eslint": "^9.23.0",
     "playwright": "^1.51.1",
+    "pnpm": "^10.7.0",
     "tsup": "^8.4.0",
     "typescript": "^5.8.2",
     "vite": "^6.2.4",