feat: add envelope feature validation

- Validate envelope_enabled config before creating envelopes
- Throw descriptive exception when feature is disabled
- Keep original error message for maximum files exceeded

Signed-off-by: Vitor Mattos <[email protected]>

Author: vitormattos

lib/Service/EnvelopeService.php

@@ -19,9 +19,6 @@
 use OCP\IL10N;
 use Sabre\DAV\UUIDUtil;
 
-/**
- * Manage envelopes (DocuSign-style digital containers for multiple documents)
- */
 class EnvelopeService {
 	public function __construct(
 		protected FileMapper $fileMapper,

lib/Service/RequestSignatureService.php

@@ -75,6 +75,11 @@ public function save(array $data): FileEntity {
 	}
 
 	public function saveEnvelope(array $data): array {
+		$isEnabled = $this->appConfig->getValueBool(Application::APP_ID, 'envelope_enabled', true);
+		if (!$isEnabled) {
+			throw new \Exception($this->l10n->t('Envelope feature is disabled'));
+		}
+
 		$envelopeName = $data['name'] ?: $this->l10n->t('Envelope %s', [date('Y-m-d H:i:s')]);
 		$userManager = $data['userManager'] ?? null;
 		$userId = $userManager instanceof IUser ? $userManager->getUID() : null;