/**
 * Serialize SSE `data:` JSON lines. Uses a BigInt replacer and catches
 * JSON.stringify failures (circular refs, exotic values) so the stream does not
 * abort mid-run — otherwise later events (e.g. `tool_end`, `result`) never reach
 * the client and the UI can stick on a running tool.
 */
export declare function stringifySSEData(value: unknown): string;