fix: normalize metadata contract fields in envelope child data

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

lib/Service/File/EnvelopeAssembler.php

@@ -40,11 +40,17 @@ public function buildEnvelopeChildData(File $childFile, \OCA\Libresign\Service\F
 		$fileData->status = $childFile->getStatus();
 		$fileData->statusText = $this->fileMapper->getTextOfStatus($childFile->getStatus());
 		$fileData->nodeId = $childFile->getNodeId();
-		$fileData->metadata = $childFile->getMetadata();
 		$childMetadata = $childFile->getMetadata() ?? [];
 		$fileData->totalPages = (int)($childMetadata['p'] ?? 0);
 		$fileData->pdfVersion = (string)($childMetadata['pdfVersion'] ?? '');
 
+		$childMetadata['p'] = $fileData->totalPages;
+		$extension = pathinfo($childFile->getName(), PATHINFO_EXTENSION);
+		if (!isset($childMetadata['extension']) || !is_string($childMetadata['extension']) || trim($childMetadata['extension']) === '') {
+			$childMetadata['extension'] = is_string($extension) && $extension !== '' ? strtolower($extension) : 'pdf';
+		}
+		$fileData->metadata = $childMetadata;
+
 		$nodeId = $childFile->getSignedNodeId() ?: $childFile->getNodeId();
 		$fileNode = $this->root->getUserFolder($childFile->getUserId())->getFirstNodeById($nodeId);
 		if ($fileNode instanceof \OCP\Files\File) {