- Replace all `from documents import index` + Whoosh writer usage across
admin.py, bulk_edit.py, tasks.py, views.py, signals/handlers.py with
`get_backend().add_or_update/remove/batch_update`
- Add `effective_content` param to `_build_tantivy_doc` / `add_or_update`
(used by signal handler to re-index root doc with version's OCR text)
- Add `wipe_index()` (renamed from `_wipe_index`) to public API; use from
`document_index --recreate` flag
- `index_optimize()` replaced with deprecation log message; Tantivy
manages segment merging automatically
- `index_reindex()` now calls `get_backend().rebuild()` + `reset_backend()`
with select_related/prefetch_related for efficiency
- `document_index` management command: add `--recreate` flag
- Status view: use `get_backend()` + dir mtime scan instead of Whoosh
`ix.last_modified()`
- Delete `documents/index.py`, `test_index.py`, `test_delayedquery.py`
- Update all tests: patch `documents.search.get_backend` (lazy imports);
`DirectoriesMixin` calls `reset_backend()` in setUp/tearDown;
`TestDocumentConsumptionFinishedSignal` likewise
- `test_api_search.py`: fix order-independent assertions for date-range
queries; fix `_rewrite_8digit_date` to be field-aware and
timezone-correct for DateTimeField vs DateField
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
