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 one is a binding: carve-lang calls carve-rs through PyO3 and embeds it at the revision recorded in Cargo.lock. A construct the engine gains is a construct this package gains the moment the pin moves, and no Python change reaches it before that.

Both constructs the corpus was waiting on 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 9ff08784 to 98de7874 (carve-rs main), in Cargo.toml and Cargo.lock together. That is the whole functional diff; the rest is the CHANGELOG.

Measured

Against carve 1436f39a, 1025 corpus pairs, wheel rebuilt for each row:

pin	diverging
9ff08784 (main)	13
98de7874	0

The 13 were nine 318-composite-figures* documents and four 319-cell-attributes-* documents. All eleven 318-composite-figures documents and all six 319-cell-attributes-bind-after-the-kind-and-alignment-markers documents now match the spec. Nothing is allowlisted or skipped; test_corpus_renders_byte_identically compares every pair and this repository has no allowlist.

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 do the other twelve.

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. It passed at the old pin too, but vacuously - the engine had no rule separating a bare opener from a decorated one, so the mutation that should break it changed nothing.

Re-run against the new pin, stripping the title and the [label] so both openers are bare changes the production. 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>

mutated to bare openers:

<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. The control asserts something now.

CHANGELOG placement

The entry goes under the existing 0.1.1 heading rather than a new one, and the "Embed carve-rs" bullet there now names 98de7874. v0.1.1 is a draft, not a release; the last released tag is v0.1.0, so the net delta a consumer sees from it is one engine move, not two. No version field is touched.