add refund logic and fix books inventory logic

app/Services/SchoolYearManagementService.php

@@ -163,6 +163,12 @@ final class SchoolYearManagementService
         if (! SchoolYearStatus::canTransition($from, SchoolYearStatus::ACTIVE)) {
             throw new InvalidArgumentException('Only draft or approved reopened school years can be activated.');
         }
+        if ($this->configurationTotalInstructionalWeeks() <= 0) {
+            throw new InvalidArgumentException('Set total instructional weeks before activating this school year.');
+        }
+        if ((int) ($year['annual_fee_includes_books'] ?? 1) !== 1) {
+            throw new InvalidArgumentException('The withdrawal refund policy requires annual tuition to include books.');
+        }
 
         $this->db->transStart();
         $activeYears = $this->schoolYearModel->where('status', SchoolYearStatus::ACTIVE)->findAll();
@@ -348,6 +354,9 @@ final class SchoolYearManagementService
             'registration_starts_on' => $this->nullableDate($payload['registration_starts_on'] ?? null),
             'registration_ends_on' => $this->nullableDate($payload['registration_ends_on'] ?? null),
             'fall_makeup_exam_on' => $this->nullableDate($payload['fall_makeup_exam_on'] ?? null),
+            'total_instructional_weeks' => $this->nullableInt($payload['total_instructional_weeks'] ?? null),
+            'annual_fee_includes_books' => 1,
+            'withdrawal_policy_version' => trim((string) ($payload['withdrawal_policy_version'] ?? 'studied_weeks_v1')) ?: 'studied_weeks_v1',
             'previous_school_year_id' => $this->nullableInt($payload['previous_school_year_id'] ?? null),
         ];
     }
@@ -377,6 +386,7 @@ final class SchoolYearManagementService
 
         $configValues = [
             'school_year' => $name,
+            'total_instructional_weeks' => (string) ($schoolYear['total_instructional_weeks'] ?? ''),
             'date_age_reference' => $ageReferenceDate,
             'refund_deadline' => $ageReferenceDate,
             'school_year_start_date' => $yearStart,
@@ -409,6 +419,13 @@ final class SchoolYearManagementService
         }
     }
 
+    private function configurationTotalInstructionalWeeks(): int
+    {
+        $weeks = filter_var($this->configurationModel->getConfig('total_instructional_weeks'), FILTER_VALIDATE_INT);
+
+        return $weeks !== false && $weeks > 0 ? (int) $weeks : 0;
+    }
+
     private function withCalendarDefaults(array $payload, string $schoolYearName): array
     {
         $calendar = $this->calendarPayloadForSchoolYear($schoolYearName);