refactor: simplify BoardContainer and update task management

- Removed initialTasks and initialStats props from KanbanBoardContainer, now using TasksContext for task management.
- Updated useTasks hook to include a simulated delay for sync indicator during task updates.
- Replaced KanbanBoardContainer with HomePageClient in the HomePage component for a cleaner structure.

src/app/page.tsx

@@ -1,6 +1,5 @@
 import { tasksService } from '@/services/tasks';
-import { KanbanBoardContainer } from '@/components/kanban/BoardContainer';
-import { HeaderContainer } from '@/components/ui/HeaderContainer';
+import { HomePageClient } from '@/components/HomePageClient';
 
 export default async function HomePage() {
   // SSR - Récupération des données côté serveur
@@ -10,19 +9,9 @@ export default async function HomePage() {
   ]);
 
   return (
-    <div className="min-h-screen bg-slate-950">
-      <HeaderContainer 
-        title="TowerControl" 
-        subtitle="Gestionnaire de tâches moderne"
-        initialStats={initialStats}
-      />
-      
-      <main className="h-[calc(100vh-120px)]">
-        <KanbanBoardContainer 
-          initialTasks={initialTasks}
-          initialStats={initialStats}
-        />
-      </main>
-    </div>
+    <HomePageClient 
+      initialTasks={initialTasks}
+      initialStats={initialStats}
+    />
   );
 }