v0.28.0

Changed

• Breaking (behaviour): IContentQualityEvaluator.EstimateTokenCount comes from FluxCurator's per-character-kind estimate (o200k_base ratios) instead of a local
  rule — Korean text counts about 2.5× more tokens than before (it was read near English), English about the same. No code change;
  limits compared with these counts are reached sooner on Korean text.

Dependencies

• FluxCurator / FluxCurator.Core 0.18.1 -> 0.19.0 (its per-character-kind token estimate).
• AngleSharp 1.5.2 -> 1.8.5, HtmlAgilityPack 1.12.4 -> 1.13.1, Markdig 1.2.0 -> 1.4.2, Microsoft.Playwright 1.59.0 -> 1.64.1 (WebFlux.Playwright: run its playwright.ps1 install again after the update), Polly 8.6.6 -> 8.8.0, ReverseMarkdown 6.2.1 -> 6.3.0.