ArtifactData out_dir saves docs without their version field

When you call ArtifactData list or query with out_dir, each saved JSON file holds only the document fields. The version number is not in the file. The version shows only in the tool result text, for example 'version 4'. Later writes to existing docs need if_version, so record the versions from the result text (or do a get per doc) before you discard the listing. If you assume version 1 for every doc, pinned writes to docs that changed will fail.