feat: add primary tag functionality to tasks

- Introduced `primaryTagId` to `Task` model and updated related components to support selecting a primary tag.
- Enhanced `TaskCard`, `EditTaskForm`, and `TagInput` to handle primary tag selection and display.
- Updated `TasksService` to manage primary tag data during task creation and updates.
- Added `emoji-regex` dependency for improved emoji handling in task titles.

src/lib/types.ts

@@ -43,6 +43,8 @@ export interface Task {
   sourceId?: string;
   tags: string[];
   tagDetails?: Tag[]; // Tags avec informations complètes (isPinned, etc.)
+  primaryTagId?: string; // ID du tag prioritaire à afficher en premier
+  primaryTag?: Tag; // Tag prioritaire avec informations complètes
   dueDate?: Date;
   completedAt?: Date;
   createdAt: Date;