fix : drawer commentaire de semaine — toasts, titre et UI Malio

- Ajoute les clés i18n manquantes (success/errors weekComment.save/delete) qui faisaient afficher la clé brute dans le toast.
- Titre du drawer simplifié à "Commentaire" ; semaine (S{n}) et plage de dates affichées sous le nom de l'employé.
- Drawer, textarea et boutons migrés vers les composants Malio UI ; bouton Annuler supprimé.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/services/employee-week-comments.ts

@@ -10,15 +10,15 @@ export const createWeekComment = async (payload: { employeeId: number; weekStart
     employee: `/api/employees/${payload.employeeId}`,
     weekStartDate: payload.weekStartDate,
     content: payload.content
-  }, { toastSuccessKey: 'success.week-comment.save', toastErrorKey: 'errors.week-comment.save' })
+  }, { toastSuccessKey: 'success.weekComment.save', toastErrorKey: 'errors.weekComment.save' })
 }
 
 export const updateWeekComment = async (id: number, content: string) => {
   const api = useApi()
-  return api.patch<EmployeeWeekComment>(`/employee_week_comments/${id}`, { content }, { toastSuccessKey: 'success.week-comment.save', toastErrorKey: 'errors.week-comment.save' })
+  return api.patch<EmployeeWeekComment>(`/employee_week_comments/${id}`, { content }, { toastSuccessKey: 'success.weekComment.save', toastErrorKey: 'errors.weekComment.save' })
 }
 
 export const deleteWeekComment = async (id: number) => {
   const api = useApi()
-  await api.delete(`/employee_week_comments/${id}`, {}, { toastSuccessKey: 'success.week-comment.delete', toastErrorKey: 'errors.week-comment.delete' })
+  await api.delete(`/employee_week_comments/${id}`, {}, { toastSuccessKey: 'success.weekComment.delete', toastErrorKey: 'errors.weekComment.delete' })
 }