/**
 * Convert string to URL-safe slug (a-z0-9_).
 * Used for file names.
 */
export function slugify(text: string): string {
  if (!text) return "";

  return text
    .toLowerCase()
    .normalize("NFD") // Decompose accented characters
    .replace(/[\u0300-\u036f]/g, "") // Remove diacritics
    .replace(/[^a-z0-9_]+/g, "_") // Replace non-alphanumeric with underscore
    .replace(/^_+|_+$/g, "") // Remove leading/trailing underscores
    .replace(/_+/g, "_"); // Collapse multiple underscores
}