export function normalizeDistinctStrings(values?: string[]) { if (!values) { return []; } const seen = new Set(); const normalized: string[] = []; for (const value of values) { if (!value) { continue; } const trimmed = value.trim(); if (!trimmed) { continue; } const key = trimmed.toLowerCase(); if (seen.has(key)) { continue; } seen.add(key); normalized.push(trimmed); } return normalized; }