Update dependency zod to v4 (#18)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

bun.lockb

@@ -26,7 +26,7 @@
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
     "tailwind-merge": "^3.0.2",
-    "zod": "^3.24.2"
+    "zod": "^4.0.0"
   },
   "devDependencies": {
     "@biomejs/biome": "1.9.4",