/**
 * Flushes any stale bytes from the OS-level stdin buffer before showing an
 * interactive Inquirer prompt.
 *
 * On Windows terminals backed by ConPTY (e.g. WezTerm), pressing Enter in one
 * @inquirer/core prompt can leave a residual byte in the OS input buffer.
 * @inquirer/core defers its first keypress handler by one setImmediate tick so
 * that stale bytes are normally discarded.  However, if the byte arrives in a
 * later I/O poll cycle (which ConPTY can do), it reaches the new prompt after
 * its handler is registered and immediately submits the default answer —
 * making the prompt appear to require two Enter presses from the user.
 *
 * Briefly putting stdin into flowing mode allows the OS to flush buffered
 * bytes during the next I/O poll.  Two setImmediate ticks are used so the
 * drain completes regardless of the current event-loop phase.
 */
export declare function drainStdin(): Promise<void>;