feat: add updatedAt field to AchievementCard and related services

- Introduced `updatedAt` property in `AchievementData`, `KeyAccomplishment`, and `Task` interfaces for improved task tracking.
- Updated `AchievementCard` UI to display the last updated date alongside completion date, enhancing user visibility.
- Adjusted `UIShowcaseClient` and `TasksService` to include `updatedAt` values, ensuring consistency across task management components.

src/services/task-management/tasks.ts

@@ -67,15 +67,18 @@ export class TasksService {
     tags?: string[];
     dueDate?: Date;
   }): Promise<Task> {
+    const status = taskData.status || 'todo';
     const task = await prisma.task.create({
       data: {
         title: taskData.title,
         description: taskData.description,
-        status: taskData.status || 'todo',
+        status: status,
         priority: taskData.priority || 'medium',
         dueDate: taskData.dueDate,
         source: 'manual', // Source manuelle
-        sourceId: `manual-${Date.now()}` // ID unique
+        sourceId: `manual-${Date.now()}`, // ID unique
+        // Si créée directement en done/archived, définir completedAt
+        completedAt: (status === 'done' || status === 'archived') ? getToday() : null
       },
       include: {
         taskTags: {
@@ -135,12 +138,16 @@ export class TasksService {
       updatedAt: getToday()
     };
 
-
-    if (updates.status === 'done' && !task.completedAt) {
+    // Logique pour completedAt : date de résolution définitive
+    if (updates.status === 'done') {
+      // Première fois qu'on marque comme done -> définir completedAt
+      updateData.completedAt = getToday();
+    } else if (updates.status === 'archived' && !task.completedAt) {
+      // Première fois qu'on archive -> définir completedAt (archiver = résoudre)
       updateData.completedAt = getToday();
-    } else if (updates.status && updates.status !== 'done' && task.completedAt) {
-      updateData.completedAt = null;
     }
+    // Si elle était déjà done/archived et qu'on change le statut,
+    // on garde la completedAt existante (ne jamais l'effacer)
 
     await prisma.task.update({
       where: { id: taskId },