* Refactor: migrate exporter/importer from tqdm to PaperlessCommand.track()
Replace direct tqdm usage in document_exporter and document_importer with
the PaperlessCommand base class and its track() method, which is backed by
Rich and handles --no-progress-bar automatically. Also removes the unused
ProgressBarMixin from mixins.py.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* Refactor: add explicit supports_progress_bar and supports_multiprocessing to all PaperlessCommand subclasses
Each management command now explicitly declares both class attributes
rather than relying on defaults, making intent unambiguous at a glance.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>