Inconsistent treatment of captions in revealjs

Run the supplied Quarto document with the revealjs format and compare the generated HTML for images inside and outside column divs. Trace the caption handling from the revealjs output path, then verify that both captions use consistent markup and that the reproduction no longer shows different structures.

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

When outputting to revealjs, Quarto is formatting captions differently depending on whether images are inside or outside column divs.

Steps to reproduce

---
title: "Figure Caption Test"
format: revealjs
---

## Slide with Column Image

::: {.column width="100%"}
![Image in column](https://placehold.co/400){width="50%"}
:::

## Slide with Standalone Image

![Image outside column](https://placehold.co/400){width="50%"}

Actual behavior

The caption "Image in column" appears in the HTML wrapped inside <figcaption>.

The caption "Image outside column" appears in the HTML inside <p class="caption">.

Expected behavior

Either one of these formats seems fine, but they should be the same to make it easy for CSS to change all captions at once.

Your environment

IDE: Positron 2025.12.2 build 5
OS: MacOS Tahoe 26.2

Quarto check output

Quarto 1.8.25
[✓] Checking environment information...
Quarto cache location: /Users/weath/Library/Caches/quarto
[✓] Checking versions of quarto binary dependencies...
Pandoc version 3.6.3: OK
Dart Sass version 1.87.0: OK
Deno version 2.3.1: OK
Typst version 0.13.0: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
Version: 1.8.25
Path: /Applications/quarto/bin

[✓] Checking tools....................OK
TinyTeX: v2024.10
Chromium: (not installed)

[✓] Checking LaTeX....................OK
Using: TinyTex
Path: /Users/weath/Library/TinyTeX/bin/universal-darwin
Version: 2024

[✓] Checking Chrome Headless....................OK
Using: Chrome found on system
Path: /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
Source: MacOS known location

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

[✓] Checking Python 3 installation....OK
Version: 3.14.2
Path: /usr/local/bin/python3
Jupyter: (None)

  Jupyter is not available in this Python installation.
  Install with python3 -m pip install jupyter

[✓] Checking R installation...........OK
Version: 4.5.2
Path: /Library/Frameworks/R.framework/Resources
LibPaths:
- /Library/Frameworks/R.framework/Versions/4.5-arm64/Resources/library
knitr: 1.50
rmarkdown: 2.29

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