feat: enhance Jira dashboard with export functionality and sprint comparison

- Added export options for CSV and JSON in `JiraDashboardPageClient`, allowing users to download metrics easily.
- Integrated `SprintComparison` component to visualize inter-sprint trends and predictions.
- Updated TODO.md to reflect completion of export metrics and sprint comparison features.

src/app/jira-dashboard/JiraDashboardPageClient.tsx

@@ -3,6 +3,7 @@
 import { useState, useEffect } from 'react';
 import { JiraConfig } from '@/lib/types';
 import { useJiraAnalytics } from '@/hooks/useJiraAnalytics';
+import { useJiraExport } from '@/hooks/useJiraExport';
 import { Header } from '@/components/ui/Header';
 import { Card, CardHeader, CardContent } from '@/components/ui/Card';
 import { Button } from '@/components/ui/Button';
@@ -15,6 +16,7 @@ import { ThroughputChart } from '@/components/jira/ThroughputChart';
 import { QualityMetrics } from '@/components/jira/QualityMetrics';
 import { PredictabilityMetrics } from '@/components/jira/PredictabilityMetrics';
 import { CollaborationMatrix } from '@/components/jira/CollaborationMatrix';
+import { SprintComparison } from '@/components/jira/SprintComparison';
 import Link from 'next/link';
 
 interface JiraDashboardPageClientProps {
@@ -23,6 +25,7 @@ interface JiraDashboardPageClientProps {
 
 export function JiraDashboardPageClient({ initialJiraConfig }: JiraDashboardPageClientProps) {
   const { analytics, isLoading, error, loadAnalytics, refreshAnalytics } = useJiraAnalytics();
+  const { isExporting, error: exportError, exportCSV, exportJSON } = useJiraExport();
   const [selectedPeriod, setSelectedPeriod] = useState<'7d' | '30d' | '3m' | 'current'>('current');
 
   useEffect(() => {
@@ -158,10 +161,33 @@ export function JiraDashboardPageClient({ initialJiraConfig }: JiraDashboardPage
               
               <div className="flex items-center gap-2">
                 {analytics && (
-                  <div className="text-xs text-[var(--muted-foreground)] px-2 py-1 bg-[var(--card)] border border-[var(--border)] rounded">
-                    💾 Données en cache
-                  </div>
+                  <>
+                    <div className="text-xs text-[var(--muted-foreground)] px-2 py-1 bg-[var(--card)] border border-[var(--border)] rounded">
+                      💾 Données en cache
+                    </div>
+                    
+                    {/* Boutons d'export */}
+                    <div className="flex items-center gap-1">
+                      <Button
+                        onClick={exportCSV}
+                        disabled={isExporting}
+                        variant="ghost"
+                        className="text-xs px-2 py-1 h-auto"
+                      >
+                        {isExporting ? '⏳' : '📊'} CSV
+                      </Button>
+                      <Button
+                        onClick={exportJSON}
+                        disabled={isExporting}
+                        variant="ghost"
+                        className="text-xs px-2 py-1 h-auto"
+                      >
+                        {isExporting ? '⏳' : '📄'} JSON
+                      </Button>
+                    </div>
+                  </>
                 )}
+                
                 <Button
                   onClick={refreshAnalytics}
                   disabled={isLoading}
@@ -185,6 +211,17 @@ export function JiraDashboardPageClient({ initialJiraConfig }: JiraDashboardPage
             </Card>
           )}
 
+          {exportError && (
+            <Card className="mb-6 border-orange-500/20 bg-orange-500/10">
+              <CardContent className="p-4">
+                <div className="flex items-center gap-2 text-orange-600 dark:text-orange-400">
+                  <span>⚠️</span>
+                  <span>Erreur d&apos;export: {exportError}</span>
+                </div>
+              </CardContent>
+            </Card>
+          )}
+
           {isLoading && !analytics && (
             <div className="grid grid-cols-1 lg:grid-cols-3 gap-6">
               {/* Skeleton loading */}
@@ -397,6 +434,19 @@ export function JiraDashboardPageClient({ initialJiraConfig }: JiraDashboardPage
                 </CardContent>
               </Card>
 
+              {/* Comparaison inter-sprints */}
+              <Card>
+                <CardHeader>
+                  <h3 className="font-semibold">📊 Comparaison inter-sprints</h3>
+                </CardHeader>
+                <CardContent>
+                  <SprintComparison 
+                    sprintHistory={analytics.velocityMetrics.sprintHistory}
+                    className="h-auto"
+                  />
+                </CardContent>
+              </Card>
+
               {/* Heatmap d'activité de l'équipe */}
               <Card>
                 <CardHeader>