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/Admin/CompetitionWinnersController.php

@@ -87,7 +87,7 @@ class CompetitionWinnersController extends BaseController
             'errors'           => session('errors'),
             'classSections'    => $classSections,
             'classRows'        => $classRows,
-            'defaultSemester'  => $this->configModel->getConfig('semester'),
+            'defaultSemester'  => getSemester(),
             'defaultSchoolYear'=> $schoolYear,
         ]);
     }
@@ -119,7 +119,7 @@ class CompetitionWinnersController extends BaseController
             'errors'           => session('errors'),
             'classSections'    => $classSections,
             'classRows'        => $classRows,
-            'defaultSemester'  => $this->configModel->getConfig('semester'),
+            'defaultSemester'  => getSemester(),
             'defaultSchoolYear'=> $schoolYear,
         ]);
     }
@@ -391,7 +391,7 @@ class CompetitionWinnersController extends BaseController
         $semester   = session('semester');
         $schoolYear = session('school_year');
         if ($semester === null || $semester === '') {
-            $semester = $this->configModel->getConfig('semester');
+            $semester = getSemester();
         }
         if ($schoolYear === null || $schoolYear === '') {
             $schoolYear = $this->configModel->getConfig('school_year');