fix: add missing cpx dependency in package.json

Author: tahmarrrr23

package.json

@@ -42,6 +42,7 @@
     "@types/node": "^24.3.0",
     "@vitest/coverage-v8": "^3.2.4",
     "@vitest/ui": "^3.2.4",
+    "cpx": "^1.5.0",
     "puppeteer": "^24.17.0",
     "rimraf": "^6.0.1",
     "typescript": "^5.9.2",