- html_scraper: add img_alt strategy (НЭБ titles from <img alt>), bold_text
strategy (Alib entries from <p><b>), Windows-1251 encoding support,
_cls_inner_texts() helper that strips inner HTML tags
- rsl: rewrite to POST SearchFilterForm[search] with CSRF token and CQL
title:(words) AND author:(word) query format
- config: update rusneb (img_alt + correct author_class) and alib_web
(encoding + bold_text) to match fixed plugin strategies
- tests: add tests/test_archives.py with network-marked tests for all six
archive plugins; НЛР and ШПИЛ marked xfail (endpoints return HTTP 404)
- presubmit: exclude network tests from default run (-m "not network")
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
