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/Database/Migrations/2026-08-16-000100_RemoveDuplicateCalendarConfigurationKeys.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace App\Database\Migrations;
+
+use CodeIgniter\Database\Migration;
+
+class RemoveDuplicateCalendarConfigurationKeys extends Migration
+{
+    private const DUPLICATE_KEYS = [
+        '1st_day_of_school',
+        'Make_up_exam',
+        'year_start_date',
+        'registration_day',
+    ];
+
+    public function up(): void
+    {
+        if (! $this->db->tableExists('configuration')) {
+            return;
+        }
+
+        $this->db->table('configuration')
+            ->whereIn('config_key', self::DUPLICATE_KEYS)
+            ->delete();
+    }
+
+    public function down(): void
+    {
+        // Obsolete duplicate keys should not be recreated.
+    }
+}

app/Database/Migrations/2026-08-16-000200_RemoveAdditionalDuplicateCalendarConfigurationKeys.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace App\Database\Migrations;
+
+use CodeIgniter\Database\Migration;
+
+class RemoveAdditionalDuplicateCalendarConfigurationKeys extends Migration
+{
+    private const DUPLICATE_KEYS = [
+        'end_of_registration',
+        'last_school_day',
+        'year_end_date',
+    ];
+
+    public function up(): void
+    {
+        if (! $this->db->tableExists('configuration')) {
+            return;
+        }
+
+        $this->db->table('configuration')
+            ->whereIn('config_key', self::DUPLICATE_KEYS)
+            ->delete();
+    }
+
+    public function down(): void
+    {
+        // Obsolete duplicate keys should not be recreated.
+    }
+}

app/Database/Migrations/2026-08-16-000300_AlignFallSemesterStartWithSchoolYearStart.php

@@ -0,0 +1,59 @@
+<?php
+
+namespace App\Database\Migrations;
+
+use CodeIgniter\Database\Migration;
+
+class AlignFallSemesterStartWithSchoolYearStart extends Migration
+{
+    public function up(): void
+    {
+        if (! $this->db->tableExists('configuration')) {
+            return;
+        }
+
+        $schoolYearStart = $this->configValue('school_year_start_date');
+        if ($schoolYearStart === null || $schoolYearStart === '') {
+            return;
+        }
+
+        $this->upsertConfigValue('fall_semester_start', $schoolYearStart);
+    }
+
+    public function down(): void
+    {
+    }
+
+    private function configValue(string $key): ?string
+    {
+        $row = $this->db->table('configuration')
+            ->select('config_value')
+            ->where('config_key', $key)
+            ->orderBy('id', 'DESC')
+            ->get(1)
+            ->getRowArray();
+
+        return $row ? (string) $row['config_value'] : null;
+    }
+
+    private function upsertConfigValue(string $key, string $value): void
+    {
+        $exists = $this->db->table('configuration')
+            ->select('id')
+            ->where('config_key', $key)
+            ->get(1)
+            ->getRowArray();
+
+        if ($exists) {
+            $this->db->table('configuration')
+                ->where('config_key', $key)
+                ->update(['config_value' => $value]);
+            return;
+        }
+
+        $this->db->table('configuration')->insert([
+            'config_key' => $key,
+            'config_value' => $value,
+        ]);
+    }
+}