fix: dohvat mjesecnih racuna za troskove

Uklanja ovisnost o workOrders.invoices i dohvaća račune direktno kroz API filtriran po mjesecu. Dodaje i display code putnog naloga u serializer kako bi prikaz u izvještaju ostao potpun.

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

frontend/src/components/dashboard/TaskCalendarWidget.jsx

@@ -3,6 +3,7 @@ import { getStatusLabel } from '../../stores/taskStore';
 import {
     downloadMonthlyCostsReport,
     downloadMonthlyServiserReport,
+    fetchMonthlyCostInvoices,
     fetchMonthlyServicerEntries,
     upsertMonthlyServicerEntry,
 } from '../../stores/fleetDashboardStore';
@@ -65,7 +66,9 @@ export default function TaskCalendarWidget({ tasks = [], notes = [], workOrders
     const [reportType, setReportType] = useState(null);
     const [downloading, setDownloading] = useState(false);
     const [manualEntries, setManualEntries] = useState([]);
+    const [costInvoices, setCostInvoices] = useState([]);
     const [loadingManualEntries, setLoadingManualEntries] = useState(false);
+    const [loadingCostInvoices, setLoadingCostInvoices] = useState(false);
     const [manualEntryTarget, setManualEntryTarget] = useState(null);
     const [savingManualEntry, setSavingManualEntry] = useState(false);
 
@@ -148,6 +151,28 @@ export default function TaskCalendarWidget({ tasks = [], notes = [], workOrders
         };
     }, [reportOpen, reportType, viewYear, viewMonth]);
 
+    useEffect(() => {
+        if (!reportOpen || reportType !== 'costs') return undefined;
+        let active = true;
+        setLoadingCostInvoices(true);
+        fetchMonthlyCostInvoices(viewYear, viewMonth + 1)
+            .then((rows) => {
+                if (!active) return;
+                setCostInvoices(Array.isArray(rows) ? rows : []);
+            })
+            .catch(() => {
+                if (!active) return;
+                setCostInvoices([]);
+            })
+            .finally(() => {
+                if (!active) return;
+                setLoadingCostInvoices(false);
+            });
+        return () => {
+            active = false;
+        };
+    }, [reportOpen, reportType, viewYear, viewMonth]);
+
     const servicerRows = useMemo(() => {
         if (reportType !== 'servicer') return [];
         const rows = [];
@@ -248,28 +273,14 @@ export default function TaskCalendarWidget({ tasks = [], notes = [], workOrders
 
     const costsRows = useMemo(() => {
         if (reportType !== 'costs') return [];
-        const monthPrefix = `${viewYear}-${String(viewMonth + 1).padStart(2, '0')}`;
-        const workOrderIds = new Set(
-            tasks
-                .filter((task) => {
-                    const key = toDateKey(task.scheduled_date);
-                    return Boolean(key && key.startsWith(monthPrefix) && task.work_order);
-                })
-                .map((task) => String(task.work_order))
-        );
-
-        return workOrders
-            .filter((workOrder) => workOrderIds.has(String(workOrder.id)) && Array.isArray(workOrder.invoices))
-            .flatMap((workOrder) => (
-                workOrder.invoices.map((invoice) => ([
-                    invoice?.datum ? new Date(invoice.datum).toLocaleDateString('hr-HR') : '-',
-                    invoice?.naziv_racuna || '-',
-                    invoice?.lokacija || '-',
-                    invoice?.opis || '-',
-                    workOrder.display_code || '-',
-                ]))
-            ));
-    }, [reportType, tasks, viewYear, viewMonth, workOrders]);
+        return costInvoices.map((invoice) => ([
+            invoice?.datum ? new Date(invoice.datum).toLocaleDateString('hr-HR') : '-',
+            invoice?.naziv_racuna || '-',
+            invoice?.lokacija || '-',
+            invoice?.opis || '-',
+            invoice?.work_order_display_code || '-',
+        ]));
+    }, [costInvoices, reportType]);
 
     const selectedDayKey = selectedDay
         ? `${viewYear}-${String(viewMonth + 1).padStart(2, '0')}-${String(selectedDay).padStart(2, '0')}`
@@ -628,7 +639,9 @@ export default function TaskCalendarWidget({ tasks = [], notes = [], workOrders
                                 )}
 
                                 {reportType === 'costs' && (
-                                    costsRows.length === 0 ? (
+                                    loadingCostInvoices ? (
+                                        <p className="px-4 py-8 text-center text-sm text-text-muted">Ucitam troskove...</p>
+                                    ) : costsRows.length === 0 ? (
                                         <p className="px-4 py-8 text-center text-sm text-text-muted">
                                             Nema troskova za {MONTH_NAMES[viewMonth]} {viewYear}.
                                         </p>