feat(schedules): add bulk delete via checkboxes

- Add BulkDeleteSchedulesTask, BulkDeleteSchedulesAction
- Add route DELETE /dashboard/schedules/bulk-destroy
- Add bulkDestroy method to ScheduleController
- Update Index.vue: select all/individual checkboxes, bulk actions bar
- Fix CheckDashboardPermission: replace naive /s$/ regex with Str::singular()
  to resolve irregular plurals (faculties→faculty, categories→category)

app/Containers/Dashboard/Tasks/Schedules/BulkDeleteSchedulesTask.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace App\Containers\Dashboard\Tasks\Schedules;
+
+use App\Containers\Schedule\Models\Schedule;
+
+class BulkDeleteSchedulesTask
+{
+    public function run(array $ids): int
+    {
+        return Schedule::whereIn('id', $ids)->delete();
+    }
+}