Fix: renewal invoices now attributed to enrollment creator, not random User::first()

The old code tried to find 'system@oc-sport.com' then fell back to
User::first() which silently attributed 222 invoices to a random
Head Trainer. Now uses enrollment.created_by as the actor — if that
user no longer exists, the invoice is skipped with an error log.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/Console/Commands/GenerateRenewalInvoices.php

@@ -73,8 +73,15 @@ public function handle(InvoiceService $invoiceService, PricingService $pricingSe
                     continue;
                 }
 
-                $systemUser = User::where('email', 'system@oc-sport.com')->first()
-                    ?? User::first();
+                $actor = User::find($enrollment->created_by);
+                if (!$actor) {
+                    Log::error('Renewal invoice skipped — enrollment has no valid created_by user', [
+                        'enrollment_id' => $enrollment->id,
+                        'created_by' => $enrollment->created_by,
+                    ]);
+                    $failed++;
+                    continue;
+                }
 
                 $invoice = $invoiceService->create([
                     'academy_id' => $enrollment->academy_id ?? $program->academy_id,
@@ -97,7 +104,7 @@ public function handle(InvoiceService $invoiceService, PricingService $pricingSe
                         'discount_amount' => $priceResult->totalDiscount,
                         'tax_amount' => 0,
                     ],
-                ], $systemUser);
+                ], $actor);
 
                 // Mark as sent immediately so it appears in payment wizard
                 $invoice->update(['status' => \App\Domain\Financial\Enums\InvoiceStatus::Sent]);