feat(Diary): implement quick create functionality for training days and enhance localization

- Added a new button for quick creation of training days in the DiaryView, improving user experience.
- Implemented logic to find the next available training slot across groups and create a training day entry.
- Enhanced localization by adding new keys for quick create messages in multiple languages, ensuring better accessibility for users.
- Updated the DiaryManager to handle quick create operations and clear errors effectively.

frontend/src/i18n/locales/de-CH.json

@@ -828,6 +828,9 @@
     "noEntries": "Keine Einträge",
     "deleteDate": "Datum löschen",
     "createNew": "Neu anlegen",
+    "quickCreate": "Schnellanlegen",
+    "quickCreateNoSlot": "Kein freier Trainingstermin gefunden (gemäß Gruppenzeiten, ein Jahr voraus).",
+    "quickCreateFailed": "Der Trainingstag konnte nicht angelegt werden.",
     "gallery": "Mitglieder-Galerie",
     "galleryCreating": "Galerie wird erstellt…",
     "selectTrainingGroup": "Trainingsgruppe auswählen",

frontend/src/i18n/locales/de-extended.json

@@ -575,6 +575,9 @@
     "noEntries": "Keine Einträge",
     "deleteDate": "Datum löschen",
     "createNew": "Neu anlegen",
+    "quickCreate": "Schnellanlegen",
+    "quickCreateNoSlot": "Kein freier Trainingstermin gefunden (gemäß Gruppenzeiten, ein Jahr voraus).",
+    "quickCreateFailed": "Der Trainingstag konnte nicht angelegt werden.",
     "gallery": "Mitglieder-Galerie",
     "galleryCreating": "Galerie wird erstellt…",
     "selectTrainingGroup": "Trainingsgruppe auswählen",

frontend/src/i18n/locales/de.json

@@ -650,6 +650,9 @@
     "noEntries": "Keine Einträge",
     "deleteDate": "Datum löschen",
     "createNew": "Neu anlegen",
+    "quickCreate": "Schnellanlegen",
+    "quickCreateNoSlot": "Kein freier Trainingstermin gefunden (gemäß Gruppenzeiten, ein Jahr voraus).",
+    "quickCreateFailed": "Der Trainingstag konnte nicht angelegt werden.",
     "gallery": "Mitglieder-Galerie",
     "galleryCreating": "Galerie wird erstellt…",
     "selectTrainingGroup": "Trainingsgruppe auswählen",

frontend/src/i18n/locales/en-AU.json

@@ -827,6 +827,9 @@
     "noEntries": "No entries",
     "deleteDate": "Delete date",
     "createNew": "Create new",
+    "quickCreate": "Quick add",
+    "quickCreateNoSlot": "No free training slot found (per group schedule, one year ahead).",
+    "quickCreateFailed": "Could not create the training day entry.",
     "gallery": "Member gallery",
     "galleryCreating": "Creating gallery…",
     "selectTrainingGroup": "Select training group",

frontend/src/i18n/locales/en-GB.json

@@ -320,6 +320,9 @@
     "noEntries": "No entries",
     "deleteDate": "Delete date",
     "createNew": "Create new",
+    "quickCreate": "Quick add",
+    "quickCreateNoSlot": "No free training slot found (per group schedule, one year ahead).",
+    "quickCreateFailed": "Could not create the training day entry.",
     "gallery": "Member gallery",
     "galleryCreating": "Creating gallery…",
     "selectTrainingGroup": "Select training group",

frontend/src/i18n/locales/en-US.json

@@ -827,6 +827,9 @@
     "noEntries": "No entries",
     "deleteDate": "Delete date",
     "createNew": "Create new",
+    "quickCreate": "Quick add",
+    "quickCreateNoSlot": "No free training slot found (per group schedule, one year ahead).",
+    "quickCreateFailed": "Could not create the training day entry.",
     "gallery": "Member gallery",
     "galleryCreating": "Creating gallery…",
     "selectTrainingGroup": "Select training group",

frontend/src/i18n/locales/es.json

@@ -793,6 +793,9 @@
     "noEntries": "No hay entradas",
     "deleteDate": "Eliminar fecha",
     "createNew": "Crear",
+    "quickCreate": "Alta rápida",
+    "quickCreateNoSlot": "No se encontró un día de entrenamiento libre (según horarios de grupos, un año adelante).",
+    "quickCreateFailed": "No se pudo crear el día de entrenamiento.",
     "gallery": "Galería de miembros",
     "galleryCreating": "Creando galería…",
     "selectTrainingGroup": "Seleccionar grupo de entrenamiento",

frontend/src/i18n/locales/fil.json

@@ -793,6 +793,9 @@
     "noEntries": "Walang entry",
     "deleteDate": "Burahin ang petsa",
     "createNew": "Lumikha ng bago",
+    "quickCreate": "Mabilis na idagdag",
+    "quickCreateNoSlot": "Walang nahanap na libreng araw ng training (ayon sa iskedyul ng grupo, isang taon pasulong).",
+    "quickCreateFailed": "Hindi malikha ang araw ng training.",
     "gallery": "Gallery ng mga kasapi",
     "galleryCreating": "Ginagawa ang gallery…",
     "selectTrainingGroup": "Pumili ng grupo ng pagsasanay",

frontend/src/i18n/locales/fr.json

@@ -793,6 +793,9 @@
     "noEntries": "Aucune entrée",
     "deleteDate": "Supprimer la date",
     "createNew": "Créer",
+    "quickCreate": "Création rapide",
+    "quickCreateNoSlot": "Aucun créneau d’entraînement libre trouvé (selon les horaires des groupes, sur un an).",
+    "quickCreateFailed": "Impossible de créer la journée d’entraînement.",
     "gallery": "Galerie des membres",
     "galleryCreating": "Création de la galerie…",
     "selectTrainingGroup": "Sélectionner un groupe d'entraînement",

frontend/src/i18n/locales/it.json

@@ -793,6 +793,9 @@
     "noEntries": "Nessuna voce",
     "deleteDate": "Elimina data",
     "createNew": "Crea",
+    "quickCreate": "Creazione rapida",
+    "quickCreateNoSlot": "Nessun giorno di allenamento libero trovato (in base agli orari dei gruppi, entro un anno).",
+    "quickCreateFailed": "Impossibile creare la giornata di allenamento.",
     "gallery": "Galleria membri",
     "galleryCreating": "Creazione galleria…",
     "selectTrainingGroup": "Seleziona gruppo di allenamento",

frontend/src/i18n/locales/ja.json

@@ -793,6 +793,9 @@
     "noEntries": "エントリがありません",
     "deleteDate": "日付を削除",
     "createNew": "新規作成",
+    "quickCreate": "クイック作成",
+    "quickCreateNoSlot": "空きの練習日が見つかりません（グループのスケジュールに基づき、1年先まで）。",
+    "quickCreateFailed": "練習日を作成できませんでした。",
     "gallery": "メンバーギャラリー",
     "galleryCreating": "ギャラリーを作成中…",
     "selectTrainingGroup": "練習グループを選択",

frontend/src/i18n/locales/pl.json

@@ -793,6 +793,9 @@
     "noEntries": "Brak wpisów",
     "deleteDate": "Usuń datę",
     "createNew": "Utwórz",
+    "quickCreate": "Szybkie dodawanie",
+    "quickCreateNoSlot": "Nie znaleziono wolnego terminu treningu (wg harmonogramów grup, rok do przodu).",
+    "quickCreateFailed": "Nie udało się utworzyć dnia treningowego.",
     "gallery": "Galeria członków",
     "galleryCreating": "Tworzenie galerii…",
     "selectTrainingGroup": "Wybierz grupę treningową",

frontend/src/i18n/locales/th.json

@@ -793,6 +793,9 @@
     "noEntries": "ไม่มีรายการ",
     "deleteDate": "ลบวันที่",
     "createNew": "สร้างใหม่",
+    "quickCreate": "เพิ่มด่วน",
+    "quickCreateNoSlot": "ไม่พบวันฝึกที่ว่าง (ตามตารางกลุ่ม ล่วงหน้าหนึ่งปี)",
+    "quickCreateFailed": "ไม่สามารถสร้างวันฝึกได้",
     "gallery": "แกลเลอรีสมาชิก",
     "galleryCreating": "กำลังสร้างแกลเลอรี…",
     "selectTrainingGroup": "เลือกกลุ่มฝึกซ้อม",

frontend/src/i18n/locales/tl.json

@@ -793,6 +793,9 @@
     "noEntries": "Walang entry",
     "deleteDate": "Burahin ang petsa",
     "createNew": "Lumikha ng bago",
+    "quickCreate": "Mabilis na idagdag",
+    "quickCreateNoSlot": "Walang nahanap na libreng araw ng training (ayon sa iskedyul ng grupo, isang taon pasulong).",
+    "quickCreateFailed": "Hindi malikha ang araw ng training.",
     "gallery": "Gallery ng mga miyembro",
     "galleryCreating": "Ginagawa ang gallery…",
     "selectTrainingGroup": "Pumili ng grupo ng pagsasanay",

frontend/src/i18n/locales/zh.json

@@ -793,6 +793,9 @@
     "noEntries": "没有条目",
     "deleteDate": "删除日期",
     "createNew": "新建",
+    "quickCreate": "快速创建",
+    "quickCreateNoSlot": "未找到空闲训练日（按小组时间表，向前查找一年）。",
+    "quickCreateFailed": "无法创建训练日。",
     "gallery": "成员图库",
     "galleryCreating": "正在生成图库…",
     "selectTrainingGroup": "选择训练组",

frontend/src/views/DiaryView.vue

@@ -11,6 +11,9 @@
                 <button v-if="date && canDeleteCurrentDate" class="btn-secondary"
                     @click="deleteCurrentDate">{{ $t('diary.deleteDate') }}</button>
                 <button @click="openNewDateDialog" class="btn-primary">{{ $t('diary.createNew') }}</button>
+                <button type="button" @click="quickCreateNextTraining" class="btn-secondary" :disabled="quickCreateBusy">
+                    {{ $t('diary.quickCreate') }}
+                </button>
             </label>
         </div>
         <!-- Training Group Selection Dialog -->
@@ -1052,7 +1055,8 @@ export default {
             isMobileView: typeof window !== 'undefined' ? window.innerWidth <= 768 : false,
             participantSearchQuery: '',
             participantFilter: 'all',
-            planGroupFilter: '__all__'
+            planGroupFilter: '__all__',
+            quickCreateBusy: false
         };
     },
     watch: {
@@ -1623,6 +1627,76 @@ export default {
             this.showTrainingGroupDialog = true;
             this.showForm = false;
         },
+
+        diaryDateKey(entry) {
+            if (!entry || entry.date == null) return '';
+            return String(entry.date).substring(0, 10);
+        },
+
+        localYyyyMmDd(d) {
+            const y = d.getFullYear();
+            const m = String(d.getMonth() + 1).padStart(2, '0');
+            const day = String(d.getDate()).padStart(2, '0');
+            return `${y}-${m}-${day}`;
+        },
+
+        findNextQuickSlotAcrossGroups(groups) {
+            if (!Array.isArray(groups) || groups.length === 0) return null;
+            const sorted = [...groups].sort((a, b) => {
+                const oa = Number.isFinite(Number(a.sortOrder)) ? Number(a.sortOrder) : 1e9;
+                const ob = Number.isFinite(Number(b.sortOrder)) ? Number(b.sortOrder) : 1e9;
+                if (oa !== ob) return oa - ob;
+                return (Number(a.id) || 0) - (Number(b.id) || 0);
+            });
+            const existing = new Set((this.dates || []).map((d) => this.diaryDateKey(d)));
+            const today = new Date();
+            for (let dayOffset = 0; dayOffset <= 366; dayOffset++) {
+                const checkDate = new Date(today.getFullYear(), today.getMonth(), today.getDate() + dayOffset);
+                const checkWeekday = checkDate.getDay();
+                const dateStr = this.localYyyyMmDd(checkDate);
+                if (existing.has(dateStr)) continue;
+                for (const g of sorted) {
+                    const times = (g.trainingTimes || [])
+                        .filter((tt) => tt.weekday === checkWeekday && tt.startTime && String(tt.startTime).trim());
+                    if (!times.length) continue;
+                    times.sort((a, b) => String(a.startTime).localeCompare(String(b.startTime))
+                        || (Number(a.id) || 0) - (Number(b.id) || 0));
+                    const time = times[0];
+                    return {
+                        date: dateStr,
+                        startTime: this.formatTimeForInput(time.startTime),
+                        endTime: this.formatTimeForInput(time.endTime),
+                    };
+                }
+            }
+            return null;
+        },
+
+        async quickCreateNextTraining() {
+            if (!this.currentClub || this.quickCreateBusy) return;
+            this.quickCreateBusy = true;
+            try {
+                const response = await apiClient.get(`/training-times/${this.currentClub}`);
+                const groups = Array.isArray(response.data) ? response.data : [];
+                const slot = this.findNextQuickSlotAcrossGroups(groups);
+                if (!slot) {
+                    this.showInfo(this.$t('messages.info'), this.$t('diary.quickCreateNoSlot'), '', 'info');
+                    return;
+                }
+                const post = await apiClient.post(`/diary/${this.currentClub}`, {
+                    date: slot.date,
+                    trainingStart: slot.startTime || null,
+                    trainingEnd: slot.endTime || null,
+                });
+                await this.refreshDates(post.data.id);
+                await this.handleDateChange();
+            } catch (error) {
+                console.error('[quickCreateNextTraining]', error);
+                this.showInfo(this.$t('messages.error'), this.$t('diary.quickCreateFailed'), '', 'error');
+            } finally {
+                this.quickCreateBusy = false;
+            }
+        },
         
         async handleDateChange() {
             this.showForm = false;
@@ -1780,8 +1854,8 @@ export default {
                     // Nimm die erste Trainingszeit für diesen Tag
                     const time = timesForWeekday[0];
                     // Prüfe, ob dieses Datum bereits existiert
-                    const dateStr = checkDate.toISOString().split('T')[0];
-                    const exists = this.dates.some(d => d.date === dateStr);
+                    const dateStr = this.localYyyyMmDd(checkDate);
+                    const exists = this.dates.some(d => this.diaryDateKey(d) === dateStr);
                     
                     if (!exists) {
                         return {
@@ -4403,6 +4477,31 @@ h3 {
     margin-bottom: 1rem;
 }
 
+/* Global `label { display: inline-flex }` würde sonst alle Kinder in eine Zeile zwängen und Buttons schrumpfen lassen. */
+.diary-header-row > label {
+    display: flex;
+    flex-wrap: wrap;
+    align-items: center;
+    gap: 0.5rem 0.75rem;
+    flex: 1 1 auto;
+    min-width: 0;
+    max-width: 100%;
+    margin: 0;
+    cursor: default;
+}
+
+.diary-header-row > label > select {
+    flex: 1 1 12rem;
+    min-width: min(12rem, 100%);
+    max-width: 100%;
+}
+
+.diary-header-row > label > .btn-primary,
+.diary-header-row > label > .btn-secondary {
+    flex-shrink: 0;
+    white-space: nowrap;
+}
+
 .gallery-trigger {
     align-self: flex-end;
 }