chore(confidence-engine): upgrade to zod 4

package-lock.json

@@ -11,7 +11,7 @@
         "next": "^14.2.0",
         "react": "^18.3.0",
         "react-dom": "^18.3.0",
-        "zod": "^3.23.0"
+        "zod": "^4.5.4"
       },
       "devDependencies": {
         "@playwright/test": "^1.62.1",
@@ -7646,9 +7646,9 @@
       }
     },
     "node_modules/zod": {
-      "version": "3.25.76",
-      "resolved": "https://registry.npmjs.org/zod/-/zod-3.25.76.tgz",
-      "integrity": "sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ==",
+      "version": "4.5.4",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-4.5.4.tgz",
+      "integrity": "sha512-sC95tT5iHHH9gtpj6A81kh+NEaRAUFN+qlUPDUbRfOMvNf5QCBqsb3WgvnpVtK5Y+4UfA6KqufotuTvMGiTlsA==",
       "license": "MIT",
       "funding": {
         "url": "https://github.com/sponsors/colinhacks"