/**
 * @purpose Scan a directory recursively for .ts/.tsx files, excluding system dirs.
 * @invariant Excludes hidden dirs (starts with `.`), EXCLUDED_DIRS, symlinks.
 * @invariant EACCES errors are silently skipped — scan continues.
 * @param dir Absolute or relative directory path to scan.
 * @returns Sorted array of absolute file paths.
 */
export declare function scanFiles(dir: string): string[];