feat(packages/ui): auto-enhance large Markdown tables

[zrosenbauer]

Summary

Automatically enhance larger Markdown tables with sorting and per-column filtering. Small tables should retain the default Rspress renderer, and authors should not need custom MDX markup.

Acceptance criteria

• A documented row threshold determines when enhancement activates.
• Headers support stable text and numeric sorting.
• Each column supports text filtering plus a clear-all action.
• Links, inline code, and other rich cell content remain intact.
• Column widths remain stable as filters change the visible rows.
• Persisted state does not cause SSR/hydration failures and tolerates unavailable storage.
• Controls are keyboard accessible, expose correct sorting state, and work on narrow viewports.
• Visual verification covers every built-in theme in light and dark modes.
• Tests cover parsing, sorting, filtering, persistence keys, and storage failure.

Prior work

Closed draft PR #143 contains an implementation spike and browser verification notes.