feat: add discreet info on story points calculation in Jira dashboard

- Included a new info banner in the overview tab explaining the use of story points in Jira.
- The banner provides default values for different task types when story points are not defined.

src/app/jira-dashboard/JiraDashboardPageClient.tsx

@@ -251,6 +251,7 @@ export function JiraDashboardPageClient({ initialJiraConfig, initialAnalytics }:
             </div>
           </div>
 
+
           {/* Contenu principal */}
           {error && (
             <AlertBanner
@@ -347,6 +348,10 @@ export function JiraDashboardPageClient({ initialJiraConfig, initialAnalytics }:
               {/* Contenu des onglets */}
               {activeTab === 'overview' && (
                 <div className="space-y-6">
+                  {/* Info discrète sur le calcul des points */}
+                  <div className="text-xs text-[var(--muted-foreground)] bg-[var(--card-column)] px-3 py-2 rounded border border-[var(--border)]">
+                    💡 <strong>Points :</strong> Utilise les story points Jira si définis, sinon Epic(13), Story(5), Task(3), Bug(2), Subtask(1)
+                  </div>
 
               {/* Graphiques principaux */}
               <div className="grid grid-cols-1 lg:grid-cols-2 gap-6">