fix: refresh notifikacija nakon PDF zahtjeva (cache hit i async polling)

Dodan _refreshNotificationsAsync() koji odmah osvjezi notifikacijski feed nakon cache hit PDF downloada, te _schedulePdfNotificationPolling() koji pollingom na 5s/20s/60s hvata Celery completion kad Pusher nije dostupan ili worker kasni.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

frontend/src/stores/fleetDashboardStore.js

@@ -737,6 +737,25 @@ export async function createWorkOrderInvoice(workOrderId, data = {}, signal = nu
     return response;
 }
 
+async function _refreshNotificationsAsync() {
+    if (!isBrowser()) return;
+    try {
+        const { fetchNotifications } = await import('./notificationStore.js');
+        await fetchNotifications();
+    } catch (_) {
+        // silent — ne blokiramo PDF flow zbog notifikacija
+    }
+}
+
+// Polling za async PDF generiranje: osveži notifikacije na 5s, 20s i 60s
+// kako bi uhvatili Celery completion bez ovisnosti o Pusher konekciji.
+function _schedulePdfNotificationPolling() {
+    if (!isBrowser()) return;
+    [5000, 20000, 60000].forEach((delay) => {
+        setTimeout(() => _refreshNotificationsAsync(), delay);
+    });
+}
+
 export async function downloadWorkOrderPdf(workOrderId) {
     if (!workOrderId) {
         throw new Error('Work order ID je obavezan.');
@@ -746,9 +765,11 @@ export async function downloadWorkOrderPdf(workOrderId) {
     if (payload?.status === 'ready' && payload?.download_url) {
         await downloadGeneratedPdfByUrl(payload.download_url, payload.filename || `${workOrderId}.work-order.pdf`);
         showToast('PDF putnog naloga je preuzet iz cache-a.', 'success');
+        _refreshNotificationsAsync();
         return payload;
     }
     showToast('PDF putnog naloga se generira u pozadini. Preuzimanje je dostupno kroz notifikaciju.', 'info');
+    _schedulePdfNotificationPolling();
     return payload;
 }
 
@@ -761,9 +782,11 @@ export async function downloadWorkOrderInvoicesPdf(workOrderId) {
     if (payload?.status === 'ready' && payload?.download_url) {
         await downloadGeneratedPdfByUrl(payload.download_url, payload.filename || `${workOrderId}.work-order-invoices.pdf`);
         showToast('PDF računa putnog naloga je preuzet iz cache-a.', 'success');
+        _refreshNotificationsAsync();
         return payload;
     }
     showToast('PDF računa se generira u pozadini. Preuzimanje je dostupno kroz notifikaciju.', 'info');
+    _schedulePdfNotificationPolling();
     return payload;
 }
 
@@ -776,9 +799,11 @@ export async function downloadWorkOrderServiceRecordsPdf(workOrderId) {
     if (payload?.status === 'ready' && payload?.download_url) {
         await downloadGeneratedPdfByUrl(payload.download_url, payload.filename || `${workOrderId}.work-order-service-records.pdf`);
         showToast('PDF servisnih zapisa je preuzet iz cache-a.', 'success');
+        _refreshNotificationsAsync();
         return payload;
     }
     showToast('PDF servisnih zapisa se generira u pozadini. Preuzimanje je dostupno kroz notifikaciju.', 'info');
+    _schedulePdfNotificationPolling();
     return payload;
 }