/**
 * Cross-tab auth storage policy (document-only).
 *
 * Credentials mirror in sessionStorage and localStorage under `aetherforge_auth`.
 * Reads prefer sessionStorage, then fall back to localStorage (survives tab close).
 *
 * Same-tab sync: login/logout dispatch the `aetherforge-auth` CustomEvent so SessionGate,
 * WebSocketProvider, and PresenceContext re-read credentials without a full reload.
 *
 * Cross-tab: intentionally NOT synced via the `storage` event. Logout in tab A clears
 * localStorage but tab B keeps in-memory session until refresh or a 401. Each tab owns
 * its WS lifecycle after auth changes in that tab.
 */

export const AUTH_STORAGE_KEY = 'aetherforge_auth';
export const AUTH_EXPIRED_FLAG_KEY = 'aetherforge_auth_expired';
export const AUTH_SYNC_EVENT = 'aetherforge-auth';

/** By policy we never listen to cross-tab `storage` events for auth. */
export const AUTH_CROSS_TAB_STORAGE_SYNC = false;

export function describeAuthStoragePolicy(): string {
  return 'dual-write session+local; same-tab aetherforge-auth; no storage-event cross-tab sync';
}