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/Helpers/GlobalConfigHelper.php

@@ -1,12 +1,15 @@
 <?php
 
 use App\Models\ConfigurationModel;
+use App\Services\SemesterRangeService;
 
 // app/Helpers/GlobalConfigHelper.php
 if (!function_exists('getSemester')) {
     function getSemester() {
         $configModel = new \App\Models\ConfigurationModel();
-        return $configModel->getConfig('semester');
+        $semester = (new SemesterRangeService($configModel))->getSemesterForDate();
+
+        return $semester !== '' ? $semester : 'Fall';
     }
 }