/** RFC4122 v4-ish GUID, using crypto when available. Shared by customer and admin session creation. */ export function generateGuid() { if (globalThis.crypto?.randomUUID) { return globalThis.crypto.randomUUID(); } const bytes = new Uint8Array(16); if (globalThis.crypto?.getRandomValues) { globalThis.crypto.getRandomValues(bytes); } else { for (let index = 0; index < bytes.length; index++) { bytes[index] = Math.floor(Math.random() * 256); } } bytes[6] = (bytes[6] & 0x0f) | 0x40; bytes[8] = (bytes[8] & 0x3f) | 0x80; const hex = Array.from(bytes, byte => byte.toString(16).padStart(2, '0')); return `${hex.slice(0, 4).join('')}-${hex.slice(4, 6).join('')}-${hex.slice(6, 8).join('')}-${hex.slice(8, 10).join('')}-${hex.slice(10, 16).join('')}`; }