export declare const CONFIG_DIR: string;
export declare const SESSION_STATE_FILE: string;
export interface ServerRuntimeState {
    pid: number;
    port: number;
    startedAt: string;
}
export declare function saveServerRuntimeState(state: ServerRuntimeState): void;
export declare function loadServerRuntimeState(): ServerRuntimeState | null;
export declare function clearServerRuntimeState(): void;
export declare function getLogDir(): string;
export declare function killProcess(pid: number): boolean;
export declare function isProcessAlive(pid: number): boolean;
/** Return today's date as YYYY-MM-DD for log file naming. */
export declare function getLogDate(): string;
/** Delete server log files older than `days` days from the log directory. */
export declare function cleanOldLogs(days?: number): void;
export interface PidFileInfo {
    pid: number;
    port?: number;
}
export declare function writePidFile(filePath: string, info: PidFileInfo): void;
export declare function readPidFile(filePath: string): PidFileInfo | null;