fix: urutan filter data siswa: Jurusan → Tingkat → Kelas

- Dropdown diurutkan: Jurusan, Tingkat Kelas, Kelas
- Jurusan di-sort by department_name (alfabetis)
- Hapus kode jurusan dari option (cukup nama)

app/Http/Controllers/StudentReportController.php

@@ -50,6 +50,7 @@ class StudentReportController extends Controller
             ->whereNotNull('department_code')
             ->where('department_code', '!=', '')
             ->get()
+            ->sortBy('department_name')
             ->pluck('department_name', 'department_code');
 
         return view('students.index', compact('students', 'classLevels', 'classNames', 'departments'));