/**
 * The session id for a `share` / `shared-read` / `await` envelope: an explicit
 * `--session-id` wins, then `PEAKS_SESSION_ID`, then the id resolved from
 * `.peaks/_runtime/session.json` under `projectRoot`, then the literal
 * `"unknown-sid"` fallback.
 *
 * `peaks sub-agent finalize` deliberately uses a DIFFERENT chain (it never
 * consults the env var), so it keeps its own resolution rather than calling
 * this helper.
 */
export declare function resolveSessionId(options: {
    sessionId?: string;
}, projectRoot: string): string;