FR: add support for div syntax in block equations, and span syntax in inline equations

I have:

• searched the issue tracker for similar issues
• installed the latest version of Quarto CLI
• formatted my issue following the Bug Reports guide

Bug description

It seems that using Div Syntax around equations breaks the cross-reference.

Steps to reproduce

---
format: html
---

Cross-reference for @eq-float works but not for @eq-div.

$$
E=mc^2
$${#eq-float}

::: {#eq-div}
$$
E=mc^2
$$
:::

Actual behavior

The document renders with a warning: WARNING ([path]/Quarto/share/filters/main.lua:14000) Unable to resolve crossref @eq-div

Expected behavior

I expected the cross-reference to render just like the one specified using the float syntax.

Your environment

• IDE: RStudio 2025.05.0 Build 496
• OS: Windows 11

Quarto check output

Quarto 1.7.31
[>] Checking versions of quarto binary dependencies...
      Pandoc version 3.6.3: OK
      Dart Sass version 1.85.1: OK
      Deno version 1.46.3: OK
      Typst version 0.13.0: OK
[>] Checking versions of quarto dependencies......OK
[>] Checking Quarto installation......OK
      Version: 1.7.31
      CodePage: 1252

[>] Checking tools....................OK
      TinyTeX: v2023.03
      Chromium: (not installed)

[>] Checking LaTeX....................OK
      Using: TinyTex
      Version: 2022

[>] Checking Chrome Headless....................OK
      Using: Chrome found on system
      Source: Windows Registry

[>] Checking basic markdown render....OK

[>] Checking Python 3 installation....(None)

      Unable to locate an installed version of Python 3.
      Install Python 3 from https://www.python.org/downloads/

[>] Checking R installation...........OK
      Version: 4.5.1
      knitr: 1.50
      rmarkdown: 2.29

[>] Checking Knitr engine render......OK