fix: premjesti kalendar widget u Layout, popravi PDF toast i Servisi danas

- TaskCalendarPortal u Layout.astro (van AnimatedPage transforma) pa fixed
  pozicija uvijek prati viewport rub bez probijanja sadržaja
- Kalendar widgeta panel koristi clipping wrapper (overflow:hidden + animirana
  width) umjesto translate3d — potpuno skriva sjenu i border kad je zatvoren
- Serviser vidi samo svoje taskove, supervisor vidi sve; neprijavljeni korisnik
  ne vidi widget (return null)
- FleetDashboardShell sluša calendar:open-task event i otvara TaskServiceRecordsModal
- Servisi danas broji Taskove (scheduled_date=danas, status aktivan/servis)
  umjesto Servisnih zapisa
- downloadGeneratedPdfByUrl hvata grešku i prikazuje Toast (npr. PDF nije
  dostupan ili je istekao)

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

frontend/src/layouts/Layout.astro

@@ -8,6 +8,7 @@ import Toast from '../components/ui/Toast.jsx';
 import ToastTrigger from '../components/ToastTrigger.jsx';
 import NetworkGuard from '../components/ui/NetworkGuard.jsx';
 import Navbar from '../components/Navbar.jsx';
+import TaskCalendarPortal from '../components/layout/TaskCalendarPortal.jsx';
 
 interface Props {
   title: string;
@@ -55,6 +56,7 @@ const isDev = import.meta.env.DEV;
     <Toast client:only="preact" />
     {!isAuthPage && isDev && <ToastTrigger client:load />}
     {!isAuthPage && <Navbar client:load minimal={minimalNav} />}
+    {!isAuthPage && <TaskCalendarPortal client:only="preact" />}
 
     <div id="main-content" class="relative z-10 flex flex-col min-h-screen max-w-6xl mx-auto px-6 md:px-8 py-6">
       <header class="flex flex-row justify-between items-end pb-6 mb-8 border-b border-border-hairline">