feat(word-html): improve preview fidelity for tracked changes and CJK layout

[kuishou68]

Summary

• render Word tracked changes and comment annotations in HTML preview instead of dropping them
• improve Word preview fidelity for style-chain spacing, indentation, page/header/footer handling, docGrid line height, and CJK font metrics
• add more reliable local font fallback lookup for common CJK family aliases on macOS

Why

The current HTML preview loses important review semantics (w:del / w:ins, comments) and diverges from Word/WPS more than necessary on Chinese documents because line height and page layout depend on style inheritance, East Asia fonts, and document grid behavior.

Validation

• dotnet restore src/officecli/officecli.csproj -nologo
• dotnet build src/officecli/officecli.csproj -nologo --no-restore

[kuishou68]

Hi @kuishou68 — this PR has merge conflicts with the current main branch. The main branch has advanced significantly (2100+ commits) since this PR was created. The HTML preview files touched by this PR (WordHandler.HtmlPreview.cs, WordHandler.HtmlPreview.Css.cs, WordHandler.HtmlPreview.Text.cs) have been substantially reworked in main.

To resolve the conflicts, this branch needs a rebase against the latest main. The FontMetricsReader.cs and SpacingConverter.cs changes should be easier to port, but the HTML preview files will need careful merging given the extent of changes on main.

Would you like me to attempt the rebase, or would you prefer to rework this on top of the latest main?