let instance: any = null;
export function getClient() {
  if (!instance) instance = createOpenEvidenceClient({ apiKey: process.env.OPENEVIDENCE_API_KEY });
  return instance;
}

async function safe<T>(fn: () => Promise<T>): Promise<T | null> {
  try { return await fn(); }
  catch (e: any) {
    if (e.status === 429) { await new Promise(r => setTimeout(r, 5000)); return fn(); }
    console.error('OpenEvidence error:', e.message);
    return null;
  }
}