/*
 * api.js
 * Single fetch wrapper used for all server communication.
 * Throws an Error with the server's detail message on non-2xx responses.
 *
 * Provides: req(method, url, body?, isForm?)
 * Depends on: nothing
 */

// ── API ──────────────────────────────────────────────────────────────────────
async function req(method, url, body = null, isForm = false) {
  const opts = {method};
  if (body) {
    if (isForm) { opts.body = body; }
    else { opts.headers = {'Content-Type':'application/json'}; opts.body = JSON.stringify(body); }
  }
  const r = await fetch(url, opts);
  if (!r.ok) {
    const e = await r.json().catch(() => ({detail:'Request failed'}));
    throw new Error(e.detail || 'Request failed');
  }
  return r.json();
}