/**
 * Returns true iff a process with `pid` is alive. Cross-platform via
 * `process.kill(pid, 0)` which is the standard liveness check — sends
 * the null signal which is just a permission probe.
 */
export declare function isProcessAlive(pid: number): boolean;
/**
 * Read the PID file. Returns the integer PID, or null when:
 *   - file missing
 *   - file empty / unparseable
 *   - PID parses but the named process is dead (stale file)
 *
 * When a stale file is detected, it's removed as a side-effect so the
 * caller doesn't have to clean it up.
 */
export declare function readBotPid(workspace?: string): number | null;
/**
 * Write the current process's PID to the file. Replaces any prior
 * content. Logs a warning if a stale PID file pointed at a different
 * still-alive PID — that means another bot is running in this
 * workspace, which is unsupported. The new bot still proceeds (we
 * don't refuse to start) but the user gets a visible hint.
 *
 * Returns the path written, for the caller's log line.
 */
export declare function writeBotPid(workspace?: string): string;
/**
 * Remove the PID file if it points at the current process. Idempotent:
 * if the file is missing or points at someone else, we leave it alone.
 * Caller is the bot's own exit handler.
 */
export declare function clearBotPid(workspace?: string): void;
/**
 * Send SIGTERM to the bot listed in the PID file. Returns:
 *   "signaled"  — PID was alive, signal sent (cross-platform). Caller
 *                 may want to give it a moment before exiting.
 *   "not-running" — no PID file or PID is dead/orphaned.
 *   "error"     — signal failed (e.g. permission denied).
 *
 * On Windows the same `process.kill(pid, "SIGTERM")` call dispatches a
 * native terminate — Node's runtime maps it to TerminateProcess. The
 * bot's SIGTERM handler runs as expected on POSIX; on Windows the
 * process exits abruptly but cleanly enough for the migration purpose.
 */
export declare function signalBotRestart(workspace?: string): {
    kind: "signaled" | "not-running" | "error";
    pid?: number;
    message?: string;
};