Preserve list paragraph IDs and shorten long bookmark names

[PiotrCzapla]

These are PRs handles longer reference ids and add ability to cross refrence list items.

The desc. below is LLM authored, but reads well:

The converter now preserves list-paragraph IDs as Word bookmarks. It also shortens long bookmark names to fit Word's limit.

Fixes

• Preserve IDs on list paragraphs. The list renderer now wraps a paragraph's text in a Word bookmark when the paragraph has an id. Previously, it emitted the text but omitted the bookmark. Paragraphs without an id remain unchanged.
• Shorten long bookmark names. Names longer than 38 characters become the first 27 characters, an underscore, and 10 hex characters from the original ID's SHA-256 hash. The hash accounts for the part that truncation would discard. Both bookmarks and references use the same mapping. The 38-character length reserves two characters for the _n suffix used for caption-number bookmarks within Word's 40-character limit.

For example, this list paragraph now supplies a bookmark for the reference:

<ol>
  <li><p id="sec-setup__mic">Connect the microphone.</p></li>
</ol>
<p>See <a href="#sec-setup__mic" data-ref="text"></a>.</p>

mdhtml #65 handles includes and appends scope suffixes before returning MDHTML. For example, scope="__mic" turns sec-setup into sec-setup__mic. The dependency minimum is mdhtml>=0.1.40. This converter consumes those IDs as supplied. The existing reference-type lookup and h1 numbering reset are unchanged.

Indentation and pagination fixes are separate in #17.

Rendered example

These recording guides demonstrate the include-to-DOCX workflow with suffixed IDs and references. Markdown and reproduction steps.

Validation

37 converter tests passed on this PR branch. Tests check list-paragraph bookmarks and grouped references to suffixed IDs. Generated documents passed schema validation and Pandoc readback. Combined with #17, 40 converter tests and 16 downstream integration tests passed.

[jph00]

I've removed the private links from this PR too.

[jph00]

When you have a draft PR, please include something at the top clearly stating what's needed to move it out of draft.

Also please try to avoid dense AI prose in PR descriptions where possible - I am not following what's happening here.

[PiotrCzapla]

When you have a draft PR, please include something at the top clearly stating what's needed to move it out of draft.

Also please try to avoid dense AI prose in PR descriptions where possible - I am not following what's happening here.

I've used drafts to indicate that I haven't reviewed the PR yet, which include fixing prose or adding short summaries. I'll figure out a better way to do it locally, so that this issues don't happen again.