init

app/page.tsx

@@ -5,7 +5,7 @@ import { DashboardAnalysisCard } from "@/components/dashboard-analysis-card";
 import { EmptyState } from "@/components/empty-state";
 import { StatCard } from "@/components/stat-card";
 import { formatDateShort, formatDistance, formatDuration, formatPace } from "@/lib/format";
-import { getDashboardAnalysis } from "@/lib/models/analysis";
+import { getDashboardAnalysis, serializeAnalysis } from "@/lib/models/analysis";
 import { listRunningActivities } from "@/lib/models/running";
 import { listStrengthWorkouts } from "@/lib/models/strength";
 
@@ -84,7 +84,7 @@ export default async function Home() {
         </div>
       </section>
 
-      <DashboardAnalysisCard analysis={dashboardAnalysis} />
+      <DashboardAnalysisCard analysis={dashboardAnalysis ? serializeAnalysis(dashboardAnalysis) : null} />
     </div>
   );
 }

app/running/[id]/page.tsx

@@ -5,7 +5,7 @@ import { RouteMapSection } from "@/components/route-map-section";
 import { StatCard } from "@/components/stat-card";
 import { formatDate, formatDistance, formatDuration, formatPace } from "@/lib/format";
 import { fetchActivityRoutePoints, getAuthorizedClient } from "@/lib/garmin/client";
-import { getLatestAnalysisForTarget } from "@/lib/models/analysis";
+import { getLatestAnalysisForTarget, serializeAnalysis } from "@/lib/models/analysis";
 import { getRunningActivity, setRunningActivityRoutePoints, type RunningActivity } from "@/lib/models/running";
 
 export const dynamic = "force-dynamic";
@@ -117,7 +117,7 @@ export default async function RunningActivityPage({
         ) : null}
       </section>
 
-      <AiAnalysisCard targetType="running" targetId={activity._id.toString()} analysis={analysis} />
+      <AiAnalysisCard targetType="running" targetId={activity._id.toString()} analysis={analysis ? serializeAnalysis(analysis) : null} />
     </div>
   );
 }

app/strength/[id]/page.tsx

@@ -3,7 +3,7 @@ import { AiAnalysisCard } from "@/components/ai-analysis-card";
 import { ExerciseProgressChart } from "@/components/exercise-progress-chart";
 import { InfoTooltip } from "@/components/info-tooltip";
 import { formatDate, formatDateShort } from "@/lib/format";
-import { getLatestAnalysisForTarget } from "@/lib/models/analysis";
+import { getLatestAnalysisForTarget, serializeAnalysis } from "@/lib/models/analysis";
 import { getStrengthWorkout, listStrengthWorkouts } from "@/lib/models/strength";
 import { exerciseE1rm, getExerciseHistory } from "@/lib/strength/stats";
 
@@ -40,7 +40,7 @@ export default async function StrengthWorkoutPage({
         {workout.notes ? <p className="mt-1.5 text-sm text-fg/70">{workout.notes}</p> : null}
       </div>
 
-      <AiAnalysisCard targetType="strength" targetId={workout._id.toString()} analysis={analysis} />
+      <AiAnalysisCard targetType="strength" targetId={workout._id.toString()} analysis={analysis ? serializeAnalysis(analysis) : null} />
 
       <div className="grid grid-cols-2 gap-2.5 sm:grid-cols-3">
         {exercisesWithHistory.map(({ exercise }, index) => {

components/ai-analysis-card.tsx

@@ -4,12 +4,12 @@ import { useActionState } from "react";
 import { Sparkles } from "lucide-react";
 import { generateAnalysisAction } from "@/app/ai/actions";
 import { formatDate } from "@/lib/format";
-import type { AiAnalysis, AiAnalysisTargetType } from "@/lib/models/analysis";
+import type { AiAnalysisTargetType, SerializedAiAnalysis } from "@/lib/models/analysis";
 
 type AiAnalysisCardProps = {
   targetType: AiAnalysisTargetType;
   targetId: string;
-  analysis: AiAnalysis | null;
+  analysis: SerializedAiAnalysis | null;
 };
 
 export function AiAnalysisCard({ targetType, targetId, analysis }: AiAnalysisCardProps) {

components/dashboard-analysis-card.tsx

@@ -4,10 +4,10 @@ import { useActionState } from "react";
 import { Sparkles } from "lucide-react";
 import { generateDashboardAnalysisAction } from "@/app/ai/actions";
 import { formatDate } from "@/lib/format";
-import type { AiAnalysis } from "@/lib/models/analysis";
+import type { SerializedAiAnalysis } from "@/lib/models/analysis";
 
 type Props = {
-  analysis: AiAnalysis | null;
+  analysis: SerializedAiAnalysis | null;
 };
 
 export function DashboardAnalysisCard({ analysis }: Props) {

components/exercise-progress-chart.tsx

@@ -1,5 +1,6 @@
 "use client";
 
+import { useEffect, useState } from "react";
 import { CartesianGrid, Line, LineChart, ResponsiveContainer, Tooltip, XAxis, YAxis } from "recharts";
 
 type ExerciseProgressChartProps = {
@@ -26,8 +27,18 @@ function E1rmDelta({ data }: { data: ExerciseProgressChartProps["data"] }) {
 }
 
 export function ExerciseProgressChart({ name, data }: ExerciseProgressChartProps) {
-  if (data.length < 2) {
-    return null;
+  const [mounted, setMounted] = useState(false);
+  useEffect(() => setMounted(true), []);
+
+  if (data.length < 2) return null;
+
+  if (!mounted) {
+    return (
+      <div className="w-full rounded-lg border border-muted/40 bg-surface p-4">
+        <div className="mb-2 h-4 w-32 animate-pulse rounded bg-muted/30" />
+        <div className="h-[150px] animate-pulse rounded bg-muted/20" />
+      </div>
+    );
   }
 
   return (

components/volume-chart.tsx

@@ -1,5 +1,6 @@
 "use client";
 
+import { useEffect, useState } from "react";
 import { Bar, BarChart, ResponsiveContainer, Tooltip, XAxis, YAxis } from "recharts";
 
 type VolumeChartProps = {
@@ -7,6 +8,18 @@ type VolumeChartProps = {
 };
 
 export function VolumeChart({ data }: VolumeChartProps) {
+  const [mounted, setMounted] = useState(false);
+  useEffect(() => setMounted(true), []);
+
+  if (!mounted) {
+    return (
+      <div className="w-full rounded-lg border border-muted/40 bg-surface p-4">
+        <div className="mb-2 h-4 w-56 animate-pulse rounded bg-muted/30" />
+        <div className="h-[180px] animate-pulse rounded bg-muted/20" />
+      </div>
+    );
+  }
+
   return (
     <div className="w-full rounded-lg border border-muted/40 bg-surface p-4">
       <div className="mb-2 text-sm text-fg/60">Wolumen treningowy (ciężar × powtórzenia)</div>

lib/format.ts

@@ -1,12 +1,12 @@
 import { format } from "date-fns";
 import { pl } from "date-fns/locale";
 
-export function formatDate(date: Date): string {
-  return format(date, "d MMMM yyyy, HH:mm", { locale: pl });
+export function formatDate(date: Date | string): string {
+  return format(new Date(date), "d MMMM yyyy, HH:mm", { locale: pl });
 }
 
-export function formatDateShort(date: Date): string {
-  return format(date, "d MMM yyyy", { locale: pl });
+export function formatDateShort(date: Date | string): string {
+  return format(new Date(date), "d MMM yyyy", { locale: pl });
 }
 
 export function formatDuration(seconds: number): string {

lib/models/analysis.ts

@@ -16,6 +16,28 @@ export type AiAnalysis = AiAnalysisInput & {
   createdAt: Date;
 };
 
+export type SerializedAiAnalysis = {
+  _id: string;
+  targetType: AiAnalysisTargetType;
+  targetId: string;
+  summary: string;
+  tips: string[];
+  model: string;
+  createdAt: string;
+};
+
+export function serializeAnalysis(analysis: AiAnalysis): SerializedAiAnalysis {
+  return {
+    _id: analysis._id.toString(),
+    targetType: analysis.targetType,
+    targetId: analysis.targetId.toString(),
+    summary: analysis.summary,
+    tips: analysis.tips,
+    model: analysis.model,
+    createdAt: analysis.createdAt.toISOString(),
+  };
+}
+
 const COLLECTION = "ai_analyses";
 
 async function getCollection() {