feat: add workday utility functions

- Introduced utility functions for workday calculations in `workday-utils.ts`, including `getPreviousWorkday`, `getNextWorkday`, `isWorkday`, and `getDayName`.
- Updated `DailyService` and `DailyPageClient` to utilize `getPreviousWorkday` for accurate date handling instead of simple date subtraction.

services/daily.ts

@@ -1,6 +1,7 @@
 import { prisma } from './database';
 import { Prisma } from '@prisma/client';
 import { DailyCheckbox, DailyView, CreateDailyCheckboxData, UpdateDailyCheckboxData, BusinessError, DailyCheckboxType, TaskStatus, TaskPriority, TaskSource } from '@/lib/types';
+import { getPreviousWorkday } from '@/lib/workday-utils';
 
 /**
  * Service pour la gestion des checkboxes daily
@@ -15,8 +16,8 @@ export class DailyService {
     const today = new Date(date);
     today.setHours(0, 0, 0, 0);
 
-    const yesterday = new Date(today);
-    yesterday.setDate(yesterday.getDate() - 1);
+    // Utiliser la logique de jour de travail précédent au lieu de jour-1
+    const yesterday = getPreviousWorkday(today);
 
     // Récupérer les checkboxes des deux jours
     const [yesterdayCheckboxes, todayCheckboxes] = await Promise.all([