Paginate the lexicon explorer

[dcellison]

Summary

• replace the incremental show more control with numbered pagination above and below the lexicon results
• show the first page, last page, nearby pages, ellipses, and previous/next arrows using the real result count
• paginate words and registered compounds through one result stream while preserving every existing search-scope distinction
• remove the decorative SVG line beneath the filters

Behaviour

Each page contains up to 50 results. The status line gives the visible range and total, such as showing 601-650 of 1,275 words, and distinguishes word, compound, and mixed result sets. Both pagers stay synchronized; they disappear when a result set fits on one page.

Search text, search field, facets, and page number now have canonical URL parameters. Explicit page changes enter browser history, Back restores the earlier page and filters, and changing a live search or facet returns to page 1 without filling the history with every keystroke.

On narrow screens, the page window contracts to the first, current, and last pages with ellipses. The filter controls also respect the available width, preventing horizontal overflow at 320 pixels.

Page changes move keyboard focus to the refreshed result list. Current-page, previous-page, and next-page states have explicit accessible labels and semantics. The voice and Humanizer pass replaced the compressed noun-stack label lexicon pages above results with the more natural pages above the lexicon results, with the same correction below the list.

Checks

• node --check site/app.js
• python3 scripts/validate_examples.py --show-warnings (1,275 entries; 0 errors; 0 warnings)
• python3 scripts/test_vocabulary_schema.py (22 tests)
• python3 scripts/content_vocabulary_decisions.py --check (64 batches; 236 decisions)
• python3 scripts/test_content_vocabulary_decisions.py (8 tests)
• python3 scripts/test_name_forms.py (20 tests)
• phonetic-neighbour baseline regenerated and compared with no diff
• python3 scripts/generate_reference.py
• python3 scripts/build_site.py
• git diff --check
• headless Chromium interaction probe at 1280 x 900 and 320 x 700, covering top and bottom navigation, URL history, filter resets, registered compounds, exact Phi-word search, focus movement, real ranges, and horizontal overflow
• visual inspection of the built desktop and mobile explorer