/**
 * Normalize an unknown thrown value into a human-readable string.
 *
 * The default `String(error)` pattern produces `[object Object]` when the
 * thrown value is a plain object — masking the real error in telemetry.
 * This utility tries, in order:
 *   1. `Error.message`
 *   2. Raw string pass-through
 *   3. `.message` property on a plain object
 *   4. `JSON.stringify` for any other object
 *   5. `String()` fallback for primitives (number, boolean, symbol, bigint)
 *   6. `"unknown error"` for null / undefined
 */
export declare function normalizeErrorMessage(error: unknown): string;
//# sourceMappingURL=errorMessage.d.ts.map