Fix: include required 'code' column when creating default group

training_groups.code is NOT NULL — the auto-created default group was
missing it, causing a constraint violation.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/Domain/Training/Services/TrainingProgramService.php

@@ -34,6 +34,7 @@ public function create(array $data, User $actor): TrainingProgram
     private function createDefaultGroup(TrainingProgram $program, User $actor): TrainingGroup
     {
         $programName = $program->name_ar ?: $program->name;
+        $code = strtoupper(substr(preg_replace('/[^a-zA-Z0-9]/', '', $program->name ?: $program->name_ar), 0, 6)) . '01';
 
         return TrainingGroup::create([
             'academy_id' => $program->academy_id,
@@ -41,6 +42,7 @@ private function createDefaultGroup(TrainingProgram $program, User $actor): Trai
             'branch_id' => $program->branch_id,
             'name' => "Group {$program->name} 1",
             'name_ar' => "مجموعة {$programName} 1",
+            'code' => $code,
             'max_capacity' => $program->max_participants,
             'current_count' => 0,
             'waitlist_count' => 0,