fix : RTT à la date du jour et affichage des congés restant

frontend/components/employees/RttTab.vue

@@ -22,8 +22,8 @@
         </button>
       </div>
       <p class="text-[16px]">
-        <span class="font-bold">RTT À LA DATE DU JOUR :</span>
-        {{ formatMinutes(summary?.availableMinutes ?? 0) }}
+        <span class="font-bold">RTT À LA SEMAINE {{ lastCompleteWeek }} : </span>
+        <span class="font-bold">{{ formatMinutes(summary?.availableMinutes ?? 0) }}</span>
       </p>
         <div class="flex justify-center">
             <button
@@ -258,6 +258,17 @@ const emit = defineEmits<{
   (event: 'submit-rtt-payment', month: number, base25Minutes: number, bonus25Minutes: number, base50Minutes: number, bonus50Minutes: number): void
 }>()
 
+// --- Last complete week number ---
+
+const lastCompleteWeek = computed(() => {
+  const now = new Date()
+  const startOfYear = new Date(now.getFullYear(), 0, 1)
+  const dayOfYear = Math.floor((now.getTime() - startOfYear.getTime()) / 86400000) + 1
+  const dayOfWeek = now.getDay() || 7 // Monday = 1, Sunday = 7
+  const currentWeek = Math.ceil((dayOfYear - dayOfWeek + 10) / 7)
+  return currentWeek - 1
+})
+
 // --- Month navigation ---
 
 const orderedMonths = [6, 7, 8, 9, 10, 11, 12, 1, 2, 3, 4, 5] as const