The table of contents works on interactive sites again, plus fixes for border utilities, llms.txt groups and the page menu's chat links.

Fixed

• The table of contents on interactive sites. With <Routes @rendermode="InteractiveServer" />, the "On this page" highlight stopped moving once the circuit started, and clicking an entry went to the home page. The scroll-spy now re-attaches when Blazor replaces the list or the headings (or changes data-toc-ids on navigation), TOC links carry the page's path (docs/setup#install; a bare #install resolves against <base href>), and same-page links, including [x](#id) in content, scroll in place and keep the path in the address bar. Sites that added their own toc.js workaround can drop it.
• The last short sections of a page never became active in the TOC. At the bottom of the page the last heading on screen is highlighted.
• border-* utilities lost to the base border colour. The *, *::before, *::after rule in shelldocs-theme.css was outside any cascade layer, so it beat Tailwind's border-destructive and friends in previews and home pages. It's in @layer base now.
• llms.txt listed a group twice when top-level pages sat on both sides of a folder ("## Pages" before and after it). Each group now appears once, in first-seen order.
• The page menu's chat links used the visitor's origin instead of SiteUrl, so a static export previewed on localhost asked about a localhost URL. With SiteUrl set they name the published page.

What's Changed

• fix: table of contents on interactive sites, border layer, llms.txt groups by @Shewart in #49
• chore: release 0.1.19-alpha by @Shewart in #50

Full Changelog: v0.1.18-alpha...v0.1.19-alpha