* Add dry-run preview to doc_batch without writing outputs
Users cannot preview a batch before it writes files, so they cannot check the planned steps and output names for a folder first.
Add a dry_run option to doc_batch that reuses discovery, returns each file's ordered steps and planned output name, and skips processing and publishing.
Test: doc_batch_dry_run_lists_outputs_without_writing failed before the change and passes after.
* Address review for pull request 6486
---------
Co-authored-by: eliets2 <287273517+eliets2@users.noreply.github.com>
