feat(platform): add audit logs and activity feed

frontend/athena/app/dashboard/page.tsx

@@ -5,6 +5,7 @@ import Link from "next/link";
 
 import SummaryCard from "@/components/common/SummaryCard";
 import { api } from "@/lib/api";
+import type { ActivityFeedItem, ApiSuccess } from "@/types/audit";
 import type { DashboardSummary, EmptyWidget } from "@/types/dashboard";
 
 function getErrorMessage(error: unknown) {
@@ -17,13 +18,19 @@ function getErrorMessage(error: unknown) {
 
 export default function DashboardPage() {
   const [summary, setSummary] = useState<DashboardSummary | null>(null);
+  const [activities, setActivities] = useState<ActivityFeedItem[]>([]);
   const [loading, setLoading] = useState(true);
   const [error, setError] = useState("");
+  const [activityError, setActivityError] = useState("");
 
   const loadSummary = useCallback(async () => {
     try {
-      const response = await api.get<DashboardSummary>("/dashboard/summary");
-      setSummary(response.data);
+      const [summaryResponse, activityResponse] = await Promise.all([
+        api.get<DashboardSummary>("/dashboard/summary"),
+        api.get<ApiSuccess<ActivityFeedItem[]>>("/activity-feed?limit=10"),
+      ]);
+      setSummary(summaryResponse.data);
+      setActivities(activityResponse.data.data);
     } catch (err) {
       setError(getErrorMessage(err));
     } finally {
@@ -31,6 +38,16 @@ export default function DashboardPage() {
     }
   }, []);
 
+  const loadActivities = useCallback(async () => {
+    setActivityError("");
+    try {
+      const response = await api.get<ApiSuccess<ActivityFeedItem[]>>("/activity-feed?limit=10");
+      setActivities(response.data.data);
+    } catch (err) {
+      setActivityError(getErrorMessage(err));
+    }
+  }, []);
+
   useEffect(() => {
     queueMicrotask(() => {
       void loadSummary();
@@ -92,7 +109,12 @@ export default function DashboardPage() {
       </section>
 
       <div className="grid gap-4 md:grid-cols-2 xl:grid-cols-4">
-        <EmptyPanel widget={summary.activities} />
+        <ActivityPanel
+          widget={summary.activities}
+          activities={activities}
+          error={activityError}
+          onReload={() => void loadActivities()}
+        />
         <EmptyPanel widget={summary.tasks} />
         <EmptyPanel widget={summary.tickets} />
         <EmptyPanel widget={summary.projects} />
@@ -101,6 +123,54 @@ export default function DashboardPage() {
   );
 }
 
+function ActivityPanel({
+  widget,
+  activities,
+  error,
+  onReload,
+}: {
+  widget: EmptyWidget;
+  activities: ActivityFeedItem[];
+  error: string;
+  onReload: () => void;
+}) {
+  return (
+    <div className="rounded-lg border bg-white p-5 md:col-span-2 xl:col-span-4">
+      <div className="mb-4 flex items-center justify-between">
+        <h2 className="font-semibold text-slate-950">{widget.title}</h2>
+        <button type="button" className="text-sm font-medium text-slate-600 hover:text-slate-950" onClick={onReload}>
+          Aktualisieren
+        </button>
+      </div>
+
+      {error ? (
+        <p className="text-sm text-red-600">{error}</p>
+      ) : activities.length === 0 ? (
+        <p className="text-sm text-slate-500">{widget.message}</p>
+      ) : (
+        <div className="divide-y">
+          {activities.map((activity) => (
+            <div key={activity.id} className="py-3">
+              <div className="flex flex-col gap-1 sm:flex-row sm:items-center sm:justify-between">
+                <p className="font-medium text-slate-950">{activity.title}</p>
+                <time className="text-xs text-slate-500" dateTime={activity.created_at}>
+                  {new Intl.DateTimeFormat("de-DE", {
+                    dateStyle: "short",
+                    timeStyle: "short",
+                  }).format(new Date(activity.created_at))}
+                </time>
+              </div>
+              <p className="mt-1 text-sm text-slate-500">
+                {activity.description} · {activity.actor || "System"}
+              </p>
+            </div>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}
+
 function EmptyPanel({ widget }: { widget: EmptyWidget }) {
   return (
     <div className="rounded-lg border bg-white p-5">