/**
 * The `spawn-helper` binaries a node-pty install may ship, given its package
 * root. Pure over (root, readdir) so it is unit-testable. Covers the prebuilt
 * layout (`prebuilds/<platform>/spawn-helper`) plus the from-source fallback
 * (`build/Release/spawn-helper`).
 */
export declare function spawnHelperPaths(root: string, readdir?: (dir: string) => string[]): string[];
/**
 * Make node-pty's `spawn-helper` executable, resolved from node-pty's REAL
 * location at runtime.
 *
 * Why this exists: the prebuilt helper must be `chmod +x` to run, and the
 * package's `postinstall` does that — but via a RELATIVE path
 * (`node_modules/node-pty/...`) that only holds when shadok-ai is the root
 * package (a dev checkout). Installed as a dependency (npx / the managed
 * `~/.shadok-ai/app`), node-pty is hoisted to the parent `node_modules` and the
 * postinstall's CWD is shadok-ai's own dir, so the chmod hits a path that isn't
 * there and silently no-ops — leaving the helper non-executable and
 * `pty.spawn()` throwing an opaque `Error: posix_spawnp failed` on the user's
 * first agent. Resolving node-pty here sidesteps every install layout.
 *
 * Best-effort and idempotent; a no-op on Windows (no spawn-helper there).
 */
export declare function ensureSpawnHelperExecutable(notify?: (line: string) => void): void;