Fixed authentication header in test_attachments_bulk.py: Changed from deprecated 'X-API-Key' header to 'Authorization: Bearer' format. ## Changes Made - tests/e2e/test_attachments_bulk.py: Updated create_test_attachment() and get_attachment() to use 'Authorization: Bearer' header (lines 28, 45) ## Verification All 11 bulk delete tests now pass: - 7 tests in test_bulk_delete_multiple_attachments.py (TestBulkDeleteMultipleAttachmentsWithConfirmation) - 1 test in test_attachments_bulk.py::TestAttachmentBulkDelete - 3 tests in test_attachments_bulk.py::TestAttachmentBulkToolbar The fix was needed because the API expects 'Authorization: Bearer <key>' format, not 'X-API-Key: <key>'.