feat: add frontend dashboard with traffic lights, timeline, and AI summary (Phase 2L)

Dashboard page at /dashboard with 5 components:
- DeadlineTrafficLights: RED/AMBER/GREEN cards with animated counts and pulse for overdue
- CaseOverviewGrid: active/new/closed case counts
- UpcomingTimeline: merged deadlines + appointments for next 7 days, grouped by day
- AISummaryCard: natural language summary generated from dashboard data
- QuickActions: shortcuts to create cases, deadlines, AI analysis, CalDAV sync

3-column responsive grid layout. Root / redirects to /dashboard.
Fetches from GET /api/dashboard with 60s auto-refresh via react-query.

frontend/src/app/(app)/dashboard/page.tsx

@@ -0,0 +1,69 @@
+"use client";
+
+import { useQuery } from "@tanstack/react-query";
+import { api } from "@/lib/api";
+import type { DashboardData } from "@/lib/types";
+import { DeadlineTrafficLights } from "@/components/dashboard/DeadlineTrafficLights";
+import { CaseOverviewGrid } from "@/components/dashboard/CaseOverviewGrid";
+import { UpcomingTimeline } from "@/components/dashboard/UpcomingTimeline";
+import { AISummaryCard } from "@/components/dashboard/AISummaryCard";
+import { QuickActions } from "@/components/dashboard/QuickActions";
+import { Loader2 } from "lucide-react";
+
+export default function DashboardPage() {
+  const { data, isLoading, error } = useQuery({
+    queryKey: ["dashboard"],
+    queryFn: () => api.get<DashboardData>("/dashboard"),
+    refetchInterval: 60_000,
+  });
+
+  if (isLoading) {
+    return (
+      <div className="flex h-full items-center justify-center">
+        <Loader2 className="h-6 w-6 animate-spin text-neutral-400" />
+      </div>
+    );
+  }
+
+  if (error || !data) {
+    return (
+      <div className="flex h-full items-center justify-center">
+        <p className="text-sm text-neutral-500">
+          Dashboard konnte nicht geladen werden.
+        </p>
+      </div>
+    );
+  }
+
+  return (
+    <div className="mx-auto max-w-6xl space-y-6">
+      <div>
+        <h1 className="text-lg font-semibold text-neutral-900">Dashboard</h1>
+        <p className="mt-0.5 text-sm text-neutral-500">
+          Fristenübersicht und Kanzlei-Status
+        </p>
+      </div>
+
+      {/* Traffic Lights — the hero section */}
+      <DeadlineTrafficLights data={data.deadline_summary} />
+
+      {/* Main content grid */}
+      <div className="grid grid-cols-1 gap-6 lg:grid-cols-3">
+        {/* Left column: Timeline (takes 2 cols) */}
+        <div className="lg:col-span-2">
+          <UpcomingTimeline
+            deadlines={data.upcoming_deadlines}
+            appointments={data.upcoming_appointments}
+          />
+        </div>
+
+        {/* Right column: Case overview, AI summary, Quick actions */}
+        <div className="space-y-6">
+          <CaseOverviewGrid data={data.case_summary} />
+          <AISummaryCard data={data} />
+          <QuickActions />
+        </div>
+      </div>
+    </div>
+  );
+}

frontend/src/app/(app)/page.tsx

@@ -1,10 +1,5 @@
-export default function DashboardPage() {
-  return (
-    <div>
-      <h1 className="text-lg font-semibold text-neutral-900">Dashboard</h1>
-      <p className="mt-1 text-sm text-neutral-500">
-        Willkommen bei KanzlAI
-      </p>
-    </div>
-  );
+import { redirect } from "next/navigation";
+
+export default function RootPage() {
+  redirect("/dashboard");
 }

frontend/src/app/globals.css

@@ -9,3 +9,18 @@ body {
   -webkit-font-smoothing: antialiased;
   -moz-osx-font-smoothing: grayscale;
 }
+
+@keyframes count-up {
+  0% {
+    transform: translateY(8px);
+    opacity: 0;
+  }
+  100% {
+    transform: translateY(0);
+    opacity: 1;
+  }
+}
+
+.animate-count-up {
+  animation: count-up 0.3s ease-out;
+}

frontend/src/components/dashboard/AISummaryCard.tsx

@@ -0,0 +1,70 @@
+"use client";
+
+import { Sparkles } from "lucide-react";
+import type { DashboardData } from "@/lib/types";
+
+interface Props {
+  data: DashboardData;
+}
+
+function generateSummary(data: DashboardData): string {
+  const parts: string[] = [];
+  const { deadline_summary: ds, case_summary: cs, upcoming_deadlines: ud } = data;
+
+  // Deadline urgency
+  if (ds.overdue_count > 0) {
+    parts.push(
+      `${ds.overdue_count} Frist${ds.overdue_count > 1 ? "en" : ""} ${ds.overdue_count > 1 ? "sind" : "ist"} überfällig und ${ds.overdue_count > 1 ? "erfordern" : "erfordert"} sofortige Aufmerksamkeit.`,
+    );
+  }
+
+  if (ds.due_this_week > 0) {
+    parts.push(
+      `${ds.due_this_week} Frist${ds.due_this_week > 1 ? "en laufen" : " läuft"} diese Woche ab.`,
+    );
+  }
+
+  // Highlight most critical upcoming deadline
+  if (ud.length > 0) {
+    const next = ud[0];
+    parts.push(
+      `Die nächste Frist ist "${next.title}" in Akte ${next.case_number}.`,
+    );
+  }
+
+  // Case activity
+  if (cs.new_this_month > 0) {
+    parts.push(
+      `${cs.new_this_month} neue Akte${cs.new_this_month > 1 ? "n" : ""} diesen Monat bei ${cs.active_count} aktiven Verfahren.`,
+    );
+  } else {
+    parts.push(`${cs.active_count} aktive Verfahren.`);
+  }
+
+  // All good
+  if (ds.overdue_count === 0 && ds.due_this_week === 0) {
+    parts.unshift("Alle Fristen sind im Zeitplan.");
+  }
+
+  return parts.join(" ");
+}
+
+export function AISummaryCard({ data }: Props) {
+  const summary = generateSummary(data);
+
+  return (
+    <div className="rounded-xl border border-neutral-200 bg-white p-5">
+      <div className="flex items-center gap-2">
+        <div className="rounded-md bg-violet-50 p-1.5">
+          <Sparkles className="h-4 w-4 text-violet-500" />
+        </div>
+        <h2 className="text-sm font-semibold text-neutral-900">
+          KI-Zusammenfassung
+        </h2>
+      </div>
+      <p className="mt-3 text-sm leading-relaxed text-neutral-700">
+        {summary}
+      </p>
+    </div>
+  );
+}

frontend/src/components/dashboard/CaseOverviewGrid.tsx

@@ -0,0 +1,55 @@
+"use client";
+
+import { FolderOpen, FolderPlus, Archive } from "lucide-react";
+import type { CaseSummary } from "@/lib/types";
+
+interface Props {
+  data: CaseSummary;
+}
+
+export function CaseOverviewGrid({ data }: Props) {
+  const items = [
+    {
+      label: "Aktive Akten",
+      value: data.active_count,
+      icon: FolderOpen,
+      color: "text-blue-600",
+      bg: "bg-blue-50",
+    },
+    {
+      label: "Neu (Monat)",
+      value: data.new_this_month,
+      icon: FolderPlus,
+      color: "text-violet-600",
+      bg: "bg-violet-50",
+    },
+    {
+      label: "Abgeschlossen",
+      value: data.closed_count,
+      icon: Archive,
+      color: "text-neutral-500",
+      bg: "bg-neutral-50",
+    },
+  ];
+
+  return (
+    <div className="rounded-xl border border-neutral-200 bg-white p-5">
+      <h2 className="text-sm font-semibold text-neutral-900">Aktenübersicht</h2>
+      <div className="mt-4 space-y-3">
+        {items.map((item) => (
+          <div key={item.label} className="flex items-center justify-between">
+            <div className="flex items-center gap-2.5">
+              <div className={`rounded-md p-1.5 ${item.bg}`}>
+                <item.icon className={`h-4 w-4 ${item.color}`} />
+              </div>
+              <span className="text-sm text-neutral-600">{item.label}</span>
+            </div>
+            <span className="text-lg font-semibold tabular-nums text-neutral-900">
+              {item.value}
+            </span>
+          </div>
+        ))}
+      </div>
+    </div>
+  );
+}

frontend/src/components/dashboard/DeadlineTrafficLights.tsx

@@ -0,0 +1,105 @@
+"use client";
+
+import { useEffect, useRef } from "react";
+import { AlertTriangle, Clock, CheckCircle } from "lucide-react";
+import type { DeadlineSummary } from "@/lib/types";
+
+function AnimatedCount({ value }: { value: number }) {
+  const ref = useRef<HTMLSpanElement>(null);
+  const prevValue = useRef(value);
+
+  useEffect(() => {
+    const el = ref.current;
+    if (!el || prevValue.current === value) return;
+
+    el.classList.remove("animate-count-up");
+    void el.offsetWidth;
+    el.classList.add("animate-count-up");
+    prevValue.current = value;
+  }, [value]);
+
+  return (
+    <span ref={ref} className="inline-block tabular-nums">
+      {value}
+    </span>
+  );
+}
+
+interface Props {
+  data: DeadlineSummary;
+  onFilter?: (filter: "overdue" | "this_week" | "ok") => void;
+}
+
+export function DeadlineTrafficLights({ data, onFilter }: Props) {
+  const cards = [
+    {
+      key: "overdue" as const,
+      label: "Überfällig",
+      count: data.overdue_count,
+      icon: AlertTriangle,
+      bg: "bg-red-50",
+      border: "border-red-200",
+      iconColor: "text-red-500",
+      countColor: "text-red-700",
+      labelColor: "text-red-600",
+      ring: data.overdue_count > 0 ? "ring-2 ring-red-300 ring-offset-1" : "",
+      pulse: data.overdue_count > 0,
+    },
+    {
+      key: "this_week" as const,
+      label: "Diese Woche",
+      count: data.due_this_week,
+      icon: Clock,
+      bg: "bg-amber-50",
+      border: "border-amber-200",
+      iconColor: "text-amber-500",
+      countColor: "text-amber-700",
+      labelColor: "text-amber-600",
+      ring: "",
+      pulse: false,
+    },
+    {
+      key: "ok" as const,
+      label: "Im Zeitplan",
+      count: data.ok_count + data.due_next_week,
+      icon: CheckCircle,
+      bg: "bg-emerald-50",
+      border: "border-emerald-200",
+      iconColor: "text-emerald-500",
+      countColor: "text-emerald-700",
+      labelColor: "text-emerald-600",
+      ring: "",
+      pulse: false,
+    },
+  ];
+
+  return (
+    <div className="grid grid-cols-1 gap-4 sm:grid-cols-3">
+      {cards.map((card) => (
+        <button
+          key={card.key}
+          onClick={() => onFilter?.(card.key)}
+          className={`group relative overflow-hidden rounded-xl border ${card.border} ${card.bg} ${card.ring} p-6 text-left transition-all hover:shadow-md active:scale-[0.98]`}
+        >
+          {card.pulse && (
+            <span className="absolute right-4 top-4 flex h-3 w-3">
+              <span className="absolute inline-flex h-full w-full animate-ping rounded-full bg-red-400 opacity-75" />
+              <span className="relative inline-flex h-3 w-3 rounded-full bg-red-500" />
+            </span>
+          )}
+          <div className="flex items-center gap-3">
+            <div className={`rounded-lg p-2 ${card.bg}`}>
+              <card.icon className={`h-5 w-5 ${card.iconColor}`} />
+            </div>
+            <span className={`text-sm font-medium ${card.labelColor}`}>
+              {card.label}
+            </span>
+          </div>
+          <div className={`mt-4 text-4xl font-bold tracking-tight ${card.countColor}`}>
+            <AnimatedCount value={card.count} />
+          </div>
+        </button>
+      ))}
+    </div>
+  );
+}

frontend/src/components/dashboard/QuickActions.tsx

@@ -0,0 +1,53 @@
+"use client";
+
+import Link from "next/link";
+import { FolderPlus, Clock, Sparkles, CalendarSync } from "lucide-react";
+
+const actions = [
+  {
+    label: "Neue Akte",
+    href: "/akten?new=1",
+    icon: FolderPlus,
+    color: "text-blue-600 bg-blue-50 hover:bg-blue-100",
+  },
+  {
+    label: "Frist eintragen",
+    href: "/fristen?new=1",
+    icon: Clock,
+    color: "text-amber-600 bg-amber-50 hover:bg-amber-100",
+  },
+  {
+    label: "AI Analyse",
+    href: "/ai",
+    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() {
+  return (
+    <div className="rounded-xl border border-neutral-200 bg-white p-5">
+      <h2 className="text-sm font-semibold text-neutral-900">
+        Schnellzugriff
+      </h2>
+      <div className="mt-3 grid grid-cols-2 gap-2">
+        {actions.map((action) => (
+          <Link
+            key={action.label}
+            href={action.href}
+            className={`flex items-center gap-2 rounded-lg px-3 py-2.5 text-sm font-medium transition-colors ${action.color}`}
+          >
+            <action.icon className="h-4 w-4" />
+            {action.label}
+          </Link>
+        ))}
+      </div>
+    </div>
+  );
+}

frontend/src/components/dashboard/UpcomingTimeline.tsx

@@ -0,0 +1,134 @@
+"use client";
+
+import { format, parseISO, isToday, isTomorrow } from "date-fns";
+import { de } from "date-fns/locale";
+import { Clock, Calendar, MapPin } from "lucide-react";
+import type { UpcomingDeadline, UpcomingAppointment } from "@/lib/types";
+
+interface Props {
+  deadlines: UpcomingDeadline[];
+  appointments: UpcomingAppointment[];
+}
+
+type TimelineItem =
+  | { type: "deadline"; date: Date; data: UpcomingDeadline }
+  | { type: "appointment"; date: Date; data: UpcomingAppointment };
+
+function formatDayLabel(date: Date): string {
+  if (isToday(date)) return "Heute";
+  if (isTomorrow(date)) return "Morgen";
+  return format(date, "EEEE, d. MMM", { locale: de });
+}
+
+export function UpcomingTimeline({ deadlines, appointments }: Props) {
+  const items: TimelineItem[] = [
+    ...deadlines.map((d) => ({
+      type: "deadline" as const,
+      date: parseISO(d.due_date),
+      data: d,
+    })),
+    ...appointments.map((a) => ({
+      type: "appointment" as const,
+      date: parseISO(a.start_at),
+      data: a,
+    })),
+  ].sort((a, b) => a.date.getTime() - b.date.getTime());
+
+  // Group by day
+  const grouped = new Map<string, TimelineItem[]>();
+  for (const item of items) {
+    const key = format(item.date, "yyyy-MM-dd");
+    const group = grouped.get(key) ?? [];
+    group.push(item);
+    grouped.set(key, group);
+  }
+
+  const empty = items.length === 0;
+
+  return (
+    <div className="rounded-xl border border-neutral-200 bg-white p-5">
+      <h2 className="text-sm font-semibold text-neutral-900">
+        Nächste 7 Tage
+      </h2>
+      {empty ? (
+        <p className="mt-6 text-center text-sm text-neutral-400">
+          Keine anstehenden Termine oder Fristen
+        </p>
+      ) : (
+        <div className="mt-4 space-y-5">
+          {Array.from(grouped.entries()).map(([dateKey, dayItems]) => (
+            <div key={dateKey}>
+              <p className="text-xs font-medium uppercase tracking-wider text-neutral-400">
+                {formatDayLabel(dayItems[0].date)}
+              </p>
+              <div className="mt-2 space-y-2">
+                {dayItems.map((item, i) => (
+                  <TimelineEntry key={`${item.type}-${i}`} item={item} />
+                ))}
+              </div>
+            </div>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}
+
+function TimelineEntry({ item }: { item: TimelineItem }) {
+  if (item.type === "deadline") {
+    const d = item.data;
+    return (
+      <div className="flex items-start gap-3 rounded-lg border border-neutral-100 bg-neutral-50/50 px-3 py-2.5">
+        <div className="mt-0.5 rounded-md bg-amber-50 p-1">
+          <Clock className="h-3.5 w-3.5 text-amber-500" />
+        </div>
+        <div className="min-w-0 flex-1">
+          <p className="truncate text-sm font-medium text-neutral-900">
+            {d.title}
+          </p>
+          <p className="mt-0.5 truncate text-xs text-neutral-500">
+            {d.case_number} · {d.case_title}
+          </p>
+        </div>
+        <span className="shrink-0 text-xs font-medium text-amber-600">
+          Frist
+        </span>
+      </div>
+    );
+  }
+
+  const a = item.data;
+  return (
+    <div className="flex items-start gap-3 rounded-lg border border-neutral-100 bg-neutral-50/50 px-3 py-2.5">
+      <div className="mt-0.5 rounded-md bg-blue-50 p-1">
+        <Calendar className="h-3.5 w-3.5 text-blue-500" />
+      </div>
+      <div className="min-w-0 flex-1">
+        <p className="truncate text-sm font-medium text-neutral-900">
+          {a.title}
+        </p>
+        <div className="mt-0.5 flex items-center gap-2 text-xs text-neutral-500">
+          <span>{format(item.date, "HH:mm")} Uhr</span>
+          {a.location && (
+            <>
+              <span className="text-neutral-300">·</span>
+              <span className="flex items-center gap-0.5 truncate">
+                <MapPin className="h-3 w-3" />
+                {a.location}
+              </span>
+            </>
+          )}
+          {a.case_number && (
+            <>
+              <span className="text-neutral-300">·</span>
+              <span>{a.case_number}</span>
+            </>
+          )}
+        </div>
+      </div>
+      <span className="shrink-0 text-xs font-medium text-blue-600">
+        Termin
+      </span>
+    </div>
+  );
+}

frontend/src/components/layout/Sidebar.tsx

@@ -12,7 +12,7 @@ import {
 } from "lucide-react";
 
 const navigation = [
-  { name: "Dashboard", href: "/", icon: LayoutDashboard },
+  { name: "Dashboard", href: "/dashboard", icon: LayoutDashboard },
   { name: "Akten", href: "/akten", icon: FolderOpen },
   { name: "Fristen", href: "/fristen", icon: Clock },
   { name: "Termine", href: "/termine", icon: Calendar },
@@ -30,10 +30,7 @@ export function Sidebar() {
       </div>
       <nav className="flex-1 space-y-0.5 p-2">
         {navigation.map((item) => {
-          const isActive =
-            item.href === "/"
-              ? pathname === "/"
-              : pathname.startsWith(item.href);
+          const isActive = pathname.startsWith(item.href);
           return (
             <Link
               key={item.href}

frontend/src/lib/types.ts

@@ -104,6 +104,51 @@ export interface Document {
   updated_at: string;
 }
 
+export interface DeadlineSummary {
+  overdue_count: number;
+  due_this_week: number;
+  due_next_week: number;
+  ok_count: number;
+}
+
+export interface CaseSummary {
+  active_count: number;
+  new_this_month: number;
+  closed_count: number;
+}
+
+export interface UpcomingDeadline {
+  id: string;
+  title: string;
+  due_date: string;
+  case_number: string;
+  case_title: string;
+  status: string;
+}
+
+export interface UpcomingAppointment {
+  id: string;
+  title: string;
+  start_at: string;
+  case_number: string | null;
+  location: string | null;
+}
+
+export interface RecentActivityItem {
+  event_type: string | null;
+  title: string;
+  case_number: string;
+  event_date: string | null;
+}
+
+export interface DashboardData {
+  deadline_summary: DeadlineSummary;
+  case_summary: CaseSummary;
+  upcoming_deadlines: UpcomingDeadline[];
+  upcoming_appointments: UpcomingAppointment[];
+  recent_activity: RecentActivityItem[];
+}
+
 export interface ApiError {
   error: string;
   status: number;