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/HomeworkTrackingController.php

@@ -26,7 +26,7 @@ class HomeworkTrackingController extends BaseController
         $this->homeworkModel = new HomeworkModel();
         $this->db            = \Config\Database::connect();
 
-        $this->semester   = (string) ($this->configModel->getConfig('semester') ?? '');
+        $this->semester   = (string) (getSemester() ?? '');
         $this->schoolYear = (string) ($this->configModel->getConfig('school_year') ?? '');
     }