feat: enhance Jira analytics with caching and force refresh

- Updated `getJiraAnalytics` to accept a `forceRefresh` parameter for optional cache bypass.
- Modified `getProjectAnalytics` to check the cache and return cached data unless forced to refresh.
- Adjusted `loadAnalytics` in `useJiraAnalytics` to trigger a forced refresh on manual updates.
- Improved UI in `JiraDashboardPageClient` to indicate when data is served from cache.

hooks/useJiraAnalytics.ts

@@ -9,13 +9,13 @@ export function useJiraAnalytics() {
   const [error, setError] = useState<string | null>(null);
   const [isPending, startTransition] = useTransition();
 
-  const loadAnalytics = useCallback(() => {
+  const loadAnalytics = useCallback((forceRefresh = false) => {
     startTransition(async () => {
       try {
         setError(null);
-        
-        const result = await getJiraAnalytics();
-        
+
+        const result = await getJiraAnalytics(forceRefresh);
+
         if (result.success && result.data) {
           setAnalytics(result.data);
         } else {
@@ -30,7 +30,7 @@ export function useJiraAnalytics() {
   }, []);
 
   const refreshAnalytics = useCallback(() => {
-    loadAnalytics();
+    loadAnalytics(true); // Force refresh quand on actualise manuellement
   }, [loadAnalytics]);
 
   return {