Update to zod 4

Ran codemod npx zod-v3-to-v4, with no changes to code base. We have a simple repo, so not a surprise that it be so easy.

Author: kevinashworth

package-lock.json

@@ -24,7 +24,7 @@
     "react-dom": "19.1.1",
     "react-virtualized-auto-sizer": "1.0.26",
     "tailwind-merge": "3.3.1",
-    "zod": "3.25.76"
+    "zod": "4.1.12"
   },
   "devDependencies": {
     "@eslint/compat": "1.4.1",