Prefer zod v4's native toJSONSchema() — make the zod-to-json-schema import lazy so v4 consumers don't need it

Context

Nuxt Content 3.15.2 already ships a native zod v4 schema path: dist/chunks/zod4.mjs builds the JSON Schema via zod v4's built-in z.toJSONSchema(schema, { target: "draft-7", ... }) (with a small date/$content override). The vendor is detected per schema (dist/module.mjs:2334 — schema.def ? "zod4" : "zod3").

Problem

Despite the native v4 path, dist/module.mjs:50 statically imports the v3-era converter at module top level:

import { zodToJsonSchema, ignoreOverride } from "zod-to-json-schema";

and dependencies still pin the v3 line (zod ^3.25.76, zod-to-json-schema ^3.25.2).

Consequences for consumers that standardize on zod v4 (stable since 4.0):

• Because the import is static, zod-to-json-schema must be resolvable in the consuming app's tree for the module to load at all — even when every collection schema is zod v4 and the native toJSONSchema() path is the one actually used.
• Docus-based apps therefore must declare both zod and zod-to-json-schema purely to satisfy Nuxt Content's module load; nuxt prepare fails without them (a recurring trap — see the comment in geoql/v-maplibre's pnpm-workspace.yaml).
• Zod v4 itself makes zod-to-json-schema obsolete for this use case: z.toJSONSchema() is built in.

Suggestion

1. Make the zod-to-json-schema import lazy — dynamic-import it inside the zod3 toJSONSchema path only (the zod4 path already uses the native API), so v4-only consumers never need the package in their tree.
2. Widen the zod dependency to include v4 (>=3.25.0 <5), and move zod/zod-to-json-schema to (optional) peerDependencies so the version the app actually uses is respected.

Happy to open a PR if this direction is welcome.

Start with dist/module.mjs:50 and the schema vendor detection around dist/module.mjs:2334, then compare the zod3 and zod4 implementations in dist/chunks/zod4.mjs. Verify the dependency declarations for zod and zod-to-json-schema. Done means zod4-only consumers can load the module without zod-to-json-schema while the zod3 path still works.