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/SlipPrinterController.php

@@ -28,7 +28,7 @@ class SlipPrinterController extends BaseController
     {
         helper(['form', 'url']);
         $this->configModel = new ConfigurationModel();
-        $this->semester = $this->configModel->getConfig('semester');
+        $this->semester = getSemester();
         $this->schoolYear = $this->configModel->getConfig('school_year');
     }
     /**
@@ -66,7 +66,7 @@ class SlipPrinterController extends BaseController
             try {
                 $printedBy = (int) (session()->get('user_id') ?? 0) ?: null;
                 $cfg = new ConfigurationModel();
-                $semester = (string)($cfg->getConfig('semester') ?? '');
+                $semester = (string)(getSemester() ?? '');
                 $logData = [
                     'school_year'  => $data['school_year'],
                     'semester'     => $semester,
@@ -325,7 +325,7 @@ class SlipPrinterController extends BaseController
             try {
                 $printedBy = (int) (session()->get('user_id') ?? 0) ?: null;
                 $cfg = new ConfigurationModel();
-                $semester = (string)($cfg->getConfig('semester') ?? '');
+                $semester = (string)(getSemester() ?? '');
                 $logData = [
                     'school_year'  => $data['school_year'],
                     'semester'     => $semester,