fix: pin zod v3 for docs to fix Astro/Starlight compatibility

Astro/Starlight uses zod v3 internally for content collections.
The monorepo catalog uses zod v4 which was causing conflicts.

Author: oddcelot

bun.lock

@@ -12,6 +12,7 @@
   "dependencies": {
     "@astrojs/starlight": "^0.37.1",
     "astro": "^5.6.1",
-    "sharp": "^0.34.2"
+    "sharp": "^0.34.2",
+    "zod": "^3.24.0"
   }
-}
+}