feat: dnevni unosi i svi dani u mjesecnom izvjestaju servisera

- Dodan model MonthlyServicerDayEntry s automatskom popunom prema tipu:
  office (08:00-16:00, Zagreb ured), vacation i sick_leave (8h bez vremena)
- Migracija 0034_monthlyservicerdayentry za novu tablicu s UniqueConstraint
- Novi ViewSet + serializer + endpoint fleet/monthly-servicer-day-entries/
  (upsert: POST za novi dan ili update za isti dan ako vec postoji)
- Backend DOCX report (_build_monthly_servicer_report_rows) sad generira
  redak za SVAKI dan u mjesecu: taskovi > rucni unos > prazan red
- TaskCalendarWidget potpuno prepisan bez mojibake znakova
  (zamjena UTF-8 specijalnih znakova ASCII ekvivalentima u string literalima)
- Tablica izvjestaja servisera: klikom na red bez naloga otvara se overlay
  s tri opcije (Rad u uredu / Bolovanje / Godisnji)
- TaskCalendarPortal: dodan calendarWorkOrders computed (svi statusi)
  kako bi report imao potpune podatke o radnom vremenu
- fetchMonthlyServicerEntries i upsertMonthlyServicerEntry u store-u

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

frontend/src/components/layout/TaskCalendarPortal.jsx

@@ -64,6 +64,17 @@ export default function TaskCalendarPortal() {
         ));
     }, [workOrders, isSupervisorNotServiser, user?.id]);
 
+    const calendarWorkOrders = useMemo(() => {
+        const base = Array.isArray(workOrders) ? workOrders : [];
+        if (isSupervisorNotServiser) {
+            return base;
+        }
+        return base.filter((item) => (
+            String(item.creator || '') === String(user?.id || '')
+            || String(item.craneInfo?.assigned_servicer || '') === String(user?.id || '')
+        ));
+    }, [workOrders, isSupervisorNotServiser, user?.id]);
+
     useEffect(() => {
         if (!user?.id) return;
         fetchServiceNotes().catch(() => {});
@@ -103,7 +114,7 @@ export default function TaskCalendarPortal() {
             <TaskCalendarWidget
                 tasks={tasks}
                 notes={notes}
-                workOrders={activeWorkOrders}
+                workOrders={calendarWorkOrders}
                 onTaskClick={handleTaskClick}
             />
             <ServiceNotesWidget