feat: add due date filter to KanbanFilters

- Introduced `showWithDueDate` option in `KanbanFilters` to filter tasks based on due dates.
- Added toggle button in the UI for users to easily enable/disable this filter.
- Updated `TasksContext` to handle the new filter state and applied filtering logic in task retrieval.
- Ensured user preferences are saved with the new filter option in `user-preferences.ts`.

src/contexts/TasksContext.tsx

@@ -60,6 +60,7 @@ export function TasksProvider({ children, initialTasks, initialTags, initialStat
     compactView: preferences.viewPreferences.compactView || false,
     swimlanesByTags: preferences.viewPreferences.swimlanesByTags || false,
     swimlanesMode: preferences.viewPreferences.swimlanesMode || 'tags',
+    showWithDueDate: preferences.kanbanFilters.showWithDueDate || false,
     // Filtres Jira
     showJiraOnly: preferences.kanbanFilters.showJiraOnly || false,
     hideJiraTasks: preferences.kanbanFilters.hideJiraTasks || false,
@@ -80,6 +81,7 @@ export function TasksProvider({ children, initialTasks, initialTags, initialStat
       priorities: newFilters.priorities,
       showCompleted: newFilters.showCompleted,
       sortBy: newFilters.sortBy,
+      showWithDueDate: newFilters.showWithDueDate,
       // Filtres Jira
       showJiraOnly: newFilters.showJiraOnly,
       hideJiraTasks: newFilters.hideJiraTasks,
@@ -138,6 +140,7 @@ export function TasksProvider({ children, initialTasks, initialTags, initialStat
     return (kanbanFilters.tags?.filter(Boolean).length || 0) + 
            (kanbanFilters.priorities?.filter(Boolean).length || 0) + 
            (kanbanFilters.search ? 1 : 0) + 
+           (kanbanFilters.showWithDueDate ? 1 : 0) +
            (kanbanFilters.jiraProjects?.filter(Boolean).length || 0) + 
            (kanbanFilters.jiraTypes?.filter(Boolean).length || 0) + 
            (kanbanFilters.showJiraOnly ? 1 : 0) + 
@@ -212,6 +215,11 @@ export function TasksProvider({ children, initialTasks, initialTags, initialStat
       );
     }
 
+    // Filtre par date de fin
+    if (kanbanFilters.showWithDueDate) {
+      filtered = filtered.filter(task => task.dueDate != null);
+    }
+
     // Tri des tâches
     if (kanbanFilters.sortBy) {
       const sortOption = getSortOption(kanbanFilters.sortBy);