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/semester_selection_helper.php

@@ -1,6 +1,7 @@
 <?php
 
 use App\Models\ConfigurationModel;
+use App\Services\SemesterRangeService;
 
 if (!function_exists('selected_teacher_semester')) {
     function selected_teacher_semester(): string
@@ -16,8 +17,7 @@ if (!function_exists('selected_teacher_semester')) {
             return ucfirst(strtolower($fallback));
         }
 
-        $config = new ConfigurationModel();
-        $configSemester = trim((string) ($config->getConfig('semester') ?? ''));
+        $configSemester = trim((string) ((new SemesterRangeService(new ConfigurationModel()))->getSemesterForDate() ?: 'Fall'));
         if ($configSemester !== '') {
             return ucfirst(strtolower($configSemester));
         }