feat(113): fakturownia integration foundation

Phase 113 complete (v3.7 Invoices):
- DB: invoices, invoice_configs, invoice_number_counters, fakturownia_integration_settings + orders.invoice_requested
- FakturowniaIntegrationRepository (multi-account via integrations.type='fakturownia')
- FakturowniaApiClient (testConnection; createInvoice/downloadPdf STUBs)
- IntegrationsRepository::updateTestResult() (reusable test-result writer)
- /settings/integrations/fakturownia (list + edit + test + delete)
- Karta Fakturownia w hubie /settings/integrations

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/Modules/Settings/IntegrationsRepository.php

@@ -124,6 +124,29 @@ final class IntegrationsRepository
         ]);
     }
 
+    public function updateTestResult(int $integrationId, string $status, ?int $httpCode, string $message): void
+    {
+        if ($integrationId <= 0) {
+            return;
+        }
+
+        $statement = $this->pdo->prepare(
+            'UPDATE integrations
+            SET last_test_status = :status,
+                last_test_http_code = :http_code,
+                last_test_message = :message,
+                last_test_at = NOW(),
+                updated_at = NOW()
+            WHERE id = :id'
+        );
+        $statement->execute([
+            'id' => $integrationId,
+            'status' => substr($status, 0, 16),
+            'http_code' => $httpCode,
+            'message' => substr($message, 0, 255),
+        ]);
+    }
+
     public function getApiKeyEncrypted(int $integrationId): ?string
     {
         if ($integrationId <= 0) {