frontend/src/utils/api.js

const API_BASE = process.env.REACT_APP_BACKEND_URL || '';

export async function apiCall(endpoint, data, options = {}) {
  const { timeout = 30000 } = options;
  const controller = new AbortController();
  const timer = setTimeout(() => controller.abort(), timeout);

  try {
    const res = await fetch(`${API_BASE}${endpoint}`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(data),
      signal: controller.signal,
    });
    clearTimeout(timer);
    if (!res.ok) throw new Error(`HTTP ${res.status}`);
    return await res.json();
  } catch (err) {
    clearTimeout(timer);
    if (err.name === 'AbortError') throw new Error('Request timed out');
    throw err;
  }
}