added online and trigger

src/utils/customerPresence.ts

@@ -0,0 +1,18 @@
+/** هم‌تراز با CustomerPresenceService::ONLINE_THRESHOLD_SECONDS روی سرور */
+export const CUSTOMER_ONLINE_THRESHOLD_MS = 2 * 60 * 1000
+
+export type CustomerPresenceKind = 'online' | 'offline' | 'never'
+
+export function getCustomerPresenceKind(
+  lastSeenAt: string | Date | null | undefined
+): CustomerPresenceKind {
+  if (!lastSeenAt) return 'never'
+  const t = lastSeenAt instanceof Date ? lastSeenAt.getTime() : new Date(lastSeenAt).getTime()
+  if (!Number.isFinite(t)) return 'never'
+  if (Date.now() - t < CUSTOMER_ONLINE_THRESHOLD_MS) return 'online'
+  return 'offline'
+}
+
+export function isCustomerOnline(lastSeenAt: string | Date | null | undefined): boolean {
+  return getCustomerPresenceKind(lastSeenAt) === 'online'
+}