feat(tasks): use platform-aware delete shortcut on task detail view

frontend/src/views/tasks/TaskDetailView.vue

@@ -573,7 +573,7 @@
 							{{ $t('task.detail.actions.repeatAfter') }}
 						</XButton>
 						<XButton
-							v-shortcut="'Shift+Delete'"
+							v-shortcut="deleteShortcut"
 							icon="trash-alt"
 							:shadow="false"
 							class="is-danger is-outlined has-no-border"
@@ -733,6 +733,9 @@ const lastProjectOrTaskProject = computed(() => lastProject.value ?? project.val
 // Use Alt+r on other platforms
 const reminderShortcut = computed(() => isAppleDevice() ? 'Shift+KeyR' : 'Alt+KeyR')
 
+// Match native OS conventions for "delete the selected item"
+const deleteShortcut = isAppleDevice() ? 'Backspace' : 'Delete'
+
 onBeforeRouteLeave(async () => {
 	if (taskNotFound.value) {
 		return