Fix semester context, attendance rosters, and billing workflows

- load global semester helpers consistently and use date-based semester defaults
- fix grading and daily attendance duplicate student/section rows
- keep attendance violations scoped to the current semester by default
- update invoice, refund, discount, payment, and financial aid flows
- add configuration cleanup migrations for duplicate calendar/semester keys
- refresh parent registration/report-card and print request handling
- update related models, services, views, cron notes, and test coverage

app/Controllers/View/ClassPreparationController.php

@@ -50,7 +50,7 @@ class ClassPreparationController extends BaseController
         $this->db = \Config\Database::connect();
 
         $this->schoolYear = $this->configModel->getConfig('school_year');
-        $this->semester = $this->configModel->getConfig('semester');
+        $this->semester = getSemester();
     }
 
     public function index()