fix(FileListService): add missing fileId field in files array

When formatting a single file (non-envelope), the files array was
missing the fileId field, causing test failures. Added fileId to
match the expected API structure.

Fixes the test error: 'Undefined array key "fileId"' in
FileListServiceTest::testFormatSingleFileStructureByNodeType

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

Author: vitormattos

lib/Service/File/FileListService.php

@@ -142,6 +142,7 @@ private function formatSingleFileData(
 		} else {
 			$file['filesCount'] = 1;
 			$file['files'] = [[
+				'fileId' => $file['id'],
 				'nodeId' => $file['nodeId'],
 				'uuid' => $file['uuid'],
 				'name' => $file['name'],