export function normalizeOptionalString(value: unknown): string | undefined {
  if (typeof value !== "string") {
    return undefined;
  }
  const trimmed = value.trim();
  return trimmed ? trimmed : undefined;
}

export function uniqueTrimmedStrings(values: readonly unknown[]): string[] {
  const seen = new Set<string>();
  const result: string[] = [];
  for (const value of values) {
    const normalized = normalizeOptionalString(value);
    if (!normalized || seen.has(normalized)) {
      continue;
    }
    seen.add(normalized);
    result.push(normalized);
  }
  return result;
}