Move the engine pin past composite figures and cell attributes

[dereuromark]

Part of markup-carve/carve#1220 (secondary-engine tracker); spec markup-carve/carve#1215, design markup-carve/carve#1122.

There is no port to write here

The tracker's checklist line for this repository reads "port parser/renderers/writer per section 4c", which describes a native engine. This crate is a wasm-bindgen wrapper around carve-rs, pinned to an exact revision in Cargo.toml with Cargo.lock committed beside it. A construct the engine gains arrives here when the pin moves, and not before.

Both constructs have landed upstream: markup-carve/carve-rs#986 (PART 9 section 4c, composite figures) and markup-carve/carve-rs#996 (a cell's attributes bind after its kind and alignment markers).

The change

The pin moves from 6f1d9bfb to 98de7874 (carve-rs main). Cargo.lock follows, and picks up pulldown-cmark and unicase, which the engine now depends on. That is the whole diff: this repository keeps no CHANGELOG, and the README deliberately does not quote the revision.

Measured

Against carve 1436f39a, artifact rebuilt with wasm-pack build --target nodejs for each row and driven through the JS API, which is what tests/corpus.mjs does:

pin	diverging
6f1d9bfb (main)	94 of 1025
98de7874	0 of 1025

The pin was far enough behind that the 94 span most of the table work (a header cell carrying scope, cell attributes, alignment, span markers, continuation rows), attribute parsing, footnote and reference resolution, semantic spans, and the language attribute. Thirteen of them are the two constructs this bump was taken for: nine 318-composite-figures* documents and four 319-cell-attributes-*.

All eleven 318-composite-figures documents and all six 319-cell-attributes-bind-after-the-kind-and-alignment-markers documents now match the spec. smoke.mjs and the AST schema check pass unchanged. Nothing is allowlisted; this repository has no allowlist and does not gain one.

Proof, both directions

At the old pin, 318-composite-figures-4:

::: figure
![lone](l.png)
^ The only panel
:::
^ Figure #: One panel is valid

rendered the pre-section-4c shape - a generic container, with the caret line surviving as a paragraph:

<div class="figure">
  <figure>
    <img src="l.png" alt="lone">
    <figcaption>The only panel</figcaption>
  </figure>
</div>
<p>^ Figure #: One panel is valid</p>

At the new pin it renders what the spec pins, and so does every other pair.

The control now discriminates

318-composite-figures-8 is the control for the clause: an opener carrying a title or a [label] must stay a generic container rather than become a figure group. At the old pin it could not have failed, and the corpus shows why directly - -8 passed while every bare-opener document diverged by rendering the same <div class="figure">. The engine had no rule separating a bare opener from a decorated one, so the assertion had nothing to catch.

At the new pin the distinction is real. The document as written:

<div class="figure">
  <p class="admonition-title">A titled figure div</p>
  <figure>
    <img src="a.png" alt="one">
    <figcaption>(a) One</figcaption>
  </figure>
</div>
<p>^ Not a group caption</p>
<div class="figure">
  <p class="div-label">g</p>
  <p>Body.</p>
</div>

and the same document with the title and the [label] stripped, so both openers are bare:

<figure class="carve-figure-group">
  <div class="carve-figure-panels">
    <figure class="carve-figure-panel">
      <img src="a.png" alt="one">
      <figcaption>(a) One</figcaption>
    </figure>
  </div>
  <figcaption>Not a group caption</figcaption>
</figure>
<figure class="carve-figure-group">
  <div class="carve-figure-panels">
    <p>Body.</p>
  </div>
</figure>

Different element, different class, and the caret line is consumed as the group caption instead of surviving as a paragraph.