Refine dashboard and RFV visuals

src/dataService.ts

@@ -165,14 +165,20 @@ export const fetchDashboardAnalytics = async (dateRange: DateRange, options?: Ca
     const path = `/analytics/dashboard?${buildDateRangeParams(dateRange).toString()}`;
     return getCachedAnalytics(path, async () => {
         try {
-            const response = await authFetch(path);
+            const response = await authFetch(path, options?.force ? { cache: 'no-store' } : {});
             if (!response.ok) return null;
             return await response.json();
         } catch (error) {
             console.error('Fetch dashboard analytics failed', error);
             return null;
         }
-    }, options);
+    }, {
+        ...options,
+        shouldCache: (data) => {
+            const metrics = data as DashboardAnalytics | null;
+            return Boolean(metrics && Array.isArray(metrics.revenueBySeller) && Array.isArray(metrics.ordersBySeller));
+        }
+    });
 };
 
 export const fetchProductAnalytics = async (dateRange: DateRange): Promise<ProductAnalyticsItem[]> => {