fix(deps): update dependency zod to v4

Author: renovate[bot]

package-lock.json

@@ -59,7 +59,7 @@
     "reading-time": "^1.5.0",
     "slugify": "^1.6.6",
     "tailwindcss": "^4.1.16",
-    "zod": "3.25.76"
+    "zod": "4.1.12"
   },
   "devDependencies": {
     "@eslint/eslintrc": "^3.3.1",