feat(calendar): Mehrfachauswahl + Bulk-Loeschen in der Listen-Ansicht

Checkbox-Spalte plus Header-Checkbox "Alle". Bulk-Aktion mit
Bestaetigung loescht ausgewaehlte Termine; Read-Only-Eintraege
werden uebersprungen.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/views/CalendarView.vue

@@ -45,10 +45,22 @@
                     optionLabel="label" optionValue="value" placeholder="Alle Kalender"
                     showClear style="min-width: 180px" />
           </div>
-          <div class="list-meta">{{ filteredListEvents.length }} Termin(e)</div>
+          <div class="list-meta-row">
+            <div class="list-meta">{{ filteredListEvents.length }} Termin(e)</div>
+            <div v-if="selectedListIds.length" class="list-bulk">
+              <span>{{ selectedListIds.length }} ausgewaehlt</span>
+              <Button icon="pi pi-trash" :label="`${selectedListIds.length} loeschen`"
+                      severity="danger" size="small" @click="deleteSelectedListEvents" />
+              <Button label="Auswahl aufheben" size="small" text @click="selectedListIds = []" />
+            </div>
+          </div>
           <table class="list-table">
             <thead>
               <tr>
+                <th class="col-check">
+                  <Checkbox v-model="allListSelected" :binary="true"
+                            @change="toggleAllListSelected" title="Alle auswaehlen" />
+                </th>
                 <th @click="toggleListSort('dtstart')" class="sortable">
                   Datum <i v-if="listSort === 'dtstart'" :class="listSortDir === 'asc' ? 'pi pi-arrow-up' : 'pi pi-arrow-down'"></i>
                 </th>
@@ -61,7 +73,14 @@
               </tr>
             </thead>
             <tbody>
-              <tr v-for="ev in filteredListEvents" :key="ev.id" class="list-row" @click="openEditEvent(ev)">
+              <tr v-for="ev in filteredListEvents" :key="ev.id" class="list-row"
+                  :class="{ selected: selectedListIds.includes(ev.id) }"
+                  @click="openEditEvent(ev)">
+                <td class="col-check" @click.stop>
+                  <Checkbox :modelValue="selectedListIds.includes(ev.id)" :binary="true"
+                            :disabled="ev._cal?.permission === 'read'"
+                            @update:modelValue="toggleListSelect(ev.id, $event)" />
+                </td>
                 <td class="col-date">
                   <div>{{ formatListDate(ev) }}</div>
                   <div v-if="!ev.all_day" class="meta-time">{{ formatListTime(ev) }}</div>
@@ -80,7 +99,7 @@
                 </td>
               </tr>
               <tr v-if="!filteredListEvents.length">
-                <td colspan="5" class="empty-row">Keine Termine gefunden.</td>
+                <td colspan="6" class="empty-row">Keine Termine gefunden.</td>
               </tr>
             </tbody>
           </table>
@@ -337,6 +356,7 @@ import InputText from 'primevue/inputtext'
 import Textarea from 'primevue/textarea'
 import Select from 'primevue/select'
 import SelectButton from 'primevue/selectbutton'
+import Checkbox from 'primevue/checkbox'
 import FullCalendar from '@fullcalendar/vue3'
 import dayGridPlugin from '@fullcalendar/daygrid'
 import timeGridPlugin from '@fullcalendar/timegrid'
@@ -368,6 +388,57 @@ const listTo = ref('')
 const listCalFilter = ref(null)
 const listSort = ref('dtstart')
 const listSortDir = ref('asc')
+const selectedListIds = ref([])
+
+const allListSelected = computed({
+  get: () => {
+    const writable = filteredListEvents.value.filter(e => e._cal?.permission !== 'read')
+    return writable.length > 0 && writable.every(e => selectedListIds.value.includes(e.id))
+  },
+  set: () => {},
+})
+
+function toggleAllListSelected() {
+  const writableIds = filteredListEvents.value
+    .filter(e => e._cal?.permission !== 'read').map(e => e.id)
+  const allSel = writableIds.length > 0 && writableIds.every(id => selectedListIds.value.includes(id))
+  if (allSel) {
+    selectedListIds.value = selectedListIds.value.filter(id => !writableIds.includes(id))
+  } else {
+    const set = new Set(selectedListIds.value)
+    writableIds.forEach(id => set.add(id))
+    selectedListIds.value = [...set]
+  }
+}
+
+function toggleListSelect(id, checked) {
+  if (checked) {
+    if (!selectedListIds.value.includes(id)) selectedListIds.value = [...selectedListIds.value, id]
+  } else {
+    selectedListIds.value = selectedListIds.value.filter(x => x !== id)
+  }
+}
+
+async function deleteSelectedListEvents() {
+  const ids = [...selectedListIds.value]
+  if (!ids.length) return
+  if (!confirm(`${ids.length} Termin(e) wirklich loeschen?`)) return
+  let ok = 0, fail = 0
+  for (const id of ids) {
+    try {
+      await apiClient.delete(`/events/${id}`)
+      ok++
+    } catch { fail++ }
+  }
+  selectedListIds.value = []
+  toast.add({
+    severity: fail ? 'warn' : 'success',
+    summary: `${ok} geloescht${fail ? `, ${fail} fehlgeschlagen` : ''}`,
+    life: 3000,
+  })
+  await loadListEvents()
+  refreshEvents()
+}
 
 const listCalOptions = computed(() => calendars.value.map(c => ({ label: c.name, value: c.id })))
 
@@ -1117,6 +1188,10 @@ onUnmounted(() => {
 .list-view { display: flex; flex-direction: column; gap: 0.75rem; }
 .list-filters { display: flex; gap: 0.5rem; align-items: center; flex-wrap: wrap; }
 .list-meta { font-size: 0.8rem; color: var(--p-text-muted-color); }
+.list-meta-row { display: flex; align-items: center; justify-content: space-between; gap: 1rem; flex-wrap: wrap; }
+.list-bulk { display: flex; align-items: center; gap: 0.5rem; font-size: 0.85rem; }
+.col-check { width: 36px; }
+.list-row.selected { background: var(--p-primary-50); }
 .list-table { width: 100%; border-collapse: collapse; font-size: 0.875rem; }
 .list-table th { text-align: left; padding: 0.5rem; border-bottom: 2px solid var(--p-surface-200); font-weight: 600; user-select: none; }
 .list-table th.sortable { cursor: pointer; }