chore(deps): bump zod from 3.25.76 to 4.3.6

Bumps [zod](https://github.com/colinhacks/zod) from 3.25.76 to 4.3.6.
- [Release notes](https://github.com/colinhacks/zod/releases)
- [Commits](colinhacks/zod@v3.25.76...v4.3.6)

---
updated-dependencies:
- dependency-name: zod
  dependency-version: 4.3.6
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package.json

@@ -41,7 +41,7 @@
     "tsx": "^4.21.0",
     "typescript": "~5.8.2",
     "vitest": "^4.0.18",
-    "zod": "^3.24.1"
+    "zod": "^4.3.6"
   },
   "version": "0.9.3",
   "license": "Apache-2.0",

packages/core/package.json

@@ -29,7 +29,7 @@
   },
   "homepage": "https://github.com/Stackbilt-dev/charter#readme",
   "dependencies": {
-    "zod": "^3.24.1"
+    "zod": "^4.3.6"
   },
   "publishConfig": {
     "access": "public"