feat(vocab): add SRS schedule date formatting and update close button text

backend/services/vocabService.js

@@ -16,6 +16,7 @@ import { Op } from 'sequelize';
 import { BISAYA_PHASE1_DIDACTICS, BISAYA_DIDACTICS_FRAGMENTS } from '../scripts/bisaya-course-phase1.js';
 
 const DAILY_SRS_LIMIT = 50;
+const SRS_SCHEDULE_TIME_ZONE = 'Europe/Berlin';
 
 export default class VocabService {
   _stripGermanNumberSeparators(value) {
@@ -317,6 +318,21 @@ export default class VocabService {
     return date.toISOString();
   }
 
+  _getSrsScheduleDateKey(value) {
+    const date = value instanceof Date ? value : new Date(value);
+    if (Number.isNaN(date.getTime())) {
+      return '';
+    }
+    const parts = new Intl.DateTimeFormat('en-US', {
+      timeZone: SRS_SCHEDULE_TIME_ZONE,
+      year: 'numeric',
+      month: '2-digit',
+      day: '2-digit'
+    }).formatToParts(date);
+    const byType = new Map(parts.map((part) => [part.type, part.value]));
+    return `${byType.get('year')}-${byType.get('month')}-${byType.get('day')}`;
+  }
+
   _clampInteger(value, { min = 0, max = 100000, fallback = 0 } = {}) {
     const numeric = Number(value);
     if (!Number.isFinite(numeric)) {
@@ -2043,8 +2059,10 @@ export default class VocabService {
         && new Date(item.nextDueAt).getTime() > now.getTime()
       ))
       .forEach((item) => {
-        const date = new Date(item.nextDueAt).toISOString().slice(0, 10);
-        upcomingByDate.set(date, (upcomingByDate.get(date) || 0) + 1);
+        const date = this._getSrsScheduleDateKey(item.nextDueAt);
+        if (date) {
+          upcomingByDate.set(date, (upcomingByDate.get(date) || 0) + 1);
+        }
       });
     const rows = validDueRows.slice(0, limit);
     const totalDueCount = validDueRows.length;