refactor: date utils and all calls

src/components/dashboard/charts/WeeklyActivityHeatmap.tsx

@@ -1,6 +1,7 @@
 'use client';
 
 import { DailyMetrics } from '@/services/metrics';
+import { parseDate, isToday } from '@/lib/date-utils';
 
 interface WeeklyActivityHeatmapProps {
   data: DailyMetrics[];
@@ -67,7 +68,7 @@ export function WeeklyActivityHeatmap({ data, className }: WeeklyActivityHeatmap
                     </div>
                     
                     {/* Indicator si jour actuel */}
-                    {new Date(day.date).toDateString() === new Date().toDateString() && (
+                    {isToday(parseDate(day.date)) && (
                       <div className="w-2 h-2 bg-blue-500 rounded-full"></div>
                     )}
                   </div>