/**
 * Bridge Lock — Read, write, and clear the `.memoire/bridge.json` lock file.
 *
 * The lock file records the PID and port of a running `memi connect` bridge so
 * that other engine instances (pull, sync, compose…) can reuse it rather than
 * starting a new server on a different port.
 *
 * Responsibilities extracted from:
 *   - MemoireEngine._readBridgeLock()  (core.ts)
 *   - memi connect write/cleanup logic (commands/connect.ts)
 */
export interface BridgeLock {
    pid: number;
    port: number;
    startedAt: string;
}
/**
 * Path to the bridge lock file inside the project's `.memoire/` directory.
 */
export declare function bridgeLockPath(projectRoot: string): string;
/**
 * Read `.memoire/bridge.json`.
 *
 * Returns the lock data if the owning process is still alive.
 * Returns `null` if the file is absent, malformed, or the PID is stale.
 * Automatically deletes stale lock files before returning null.
 */
export declare function readBridgeLock(projectRoot: string): Promise<BridgeLock | null>;
/**
 * Write `.memoire/bridge.json` with the current bridge PID and port.
 * Creates the `.memoire/` directory if it doesn't exist.
 */
export declare function writeBridgeLock(projectRoot: string, port: number, pid?: number): Promise<void>;
/**
 * Delete `.memoire/bridge.json`.
 * Safe to call even when the file doesn't exist (errors are swallowed).
 */
export declare function clearBridgeLock(projectRoot: string): Promise<void>;