/**
 * `buildJsonSchema` — pure overlay that merges describe() metadata onto a
 * base JSON Schema (from derivePersistedSchema) as `x-` extension keys.
 *
 * When no base JSON Schema is available (non-zod / unknown validator),
 * builds a minimal `{ type:'object', properties }` from describe()'s field
 * type tags. No static `import 'zod'` — validator derivation stays lazy.
 *
 * @module
 */
import type { CollectionDescription } from './describe.js';
/** Overlay describe() metadata onto a base JSON Schema (or build a minimal one). */
export declare function buildJsonSchema(desc: CollectionDescription, base?: Record<string, unknown> | null): object;