Update dependency vitest to v4 [SECURITY]

Author: renovate[bot]

package.json

@@ -37,7 +37,7 @@
     "eslint-plugin-import": "^2.32.0",
     "openclaw": "2026.6.1",
     "typescript": "~5.9.0",
-    "vitest": "^2.0.0"
+    "vitest": "^4.0.0"
   },
   "engines": {
     "node": ">=20"