feat: Phase B — interactive dashboard, breadcrumbs, clickable navigation

- Breadcrumb component: reusable nav with items array (label+href)
- DeadlineTrafficLights: buttons → Links to /fristen?status={filter}
- CaseOverviewGrid: static metrics → clickable Links to /cases?status={filter}
- UpcomingTimeline: items → clickable Links to /fristen/{id} or /termine/{id}
  with case number links and hover chevron
- QuickActions: swap CalDAV Sync for "Neuer Termin" → /termine/neu,
  fix "Frist eintragen" → /fristen/neu
- AISummaryCard: add RefreshCw button with spinning animation
- RecentActivityList: new component showing recent case events
- DeadlineList: accept initialStatus prop, add this_week/ok filters
- fristen/page.tsx: read searchParams.status for initial filter
- Add breadcrumbs to dashboard, fristen, cases, termine pages
- Add RecentActivity type, update DashboardData type

frontend/src/components/dashboard/QuickActions.tsx

@@ -1,7 +1,7 @@
 "use client";
 
 import Link from "next/link";
-import { FolderPlus, Clock, Sparkles, CalendarSync } from "lucide-react";
+import { FolderPlus, Clock, Sparkles, CalendarPlus } from "lucide-react";
 
 const actions = [
   {
@@ -12,22 +12,22 @@ const actions = [
   },
   {
     label: "Frist eintragen",
-    href: "/fristen",
+    href: "/fristen/neu",
     icon: Clock,
     color: "text-amber-600 bg-amber-50 hover:bg-amber-100",
   },
+  {
+    label: "Neuer Termin",
+    href: "/termine/neu",
+    icon: CalendarPlus,
+    color: "text-emerald-600 bg-emerald-50 hover:bg-emerald-100",
+  },
   {
     label: "AI Analyse",
     href: "/ai/extract",
     icon: Sparkles,
     color: "text-violet-600 bg-violet-50 hover:bg-violet-100",
   },
-  {
-    label: "CalDAV Sync",
-    href: "/einstellungen",
-    icon: CalendarSync,
-    color: "text-emerald-600 bg-emerald-50 hover:bg-emerald-100",
-  },
 ];
 
 export function QuickActions() {