/**
 * Formats a JSON Schema `default` value as a literal usable in target-language
 * inline property initialization (Kotlin `val`, Swift `let`).
 *
 * Returns `undefined` when the value cannot be safely emitted as an inline
 * literal — caller should treat that as "no default."
 *
 * Supported:
 *   - strings (escaped via JSON.stringify, which produces double-quoted form
 *     valid in both Kotlin and Swift for printable ASCII; verify if your
 *     fixtures contain unusual characters)
 *   - finite numbers
 *   - booleans
 *
 * Not supported (returns undefined):
 *   - null / undefined
 *   - arrays, objects (require language-specific literal syntax)
 *   - non-finite numbers
 */
export declare function formatPrimitiveDefault(value: unknown): string | undefined;