Copy button missing in Bibtex when using citation

[xuefeng-xu]

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

Copy botton missing in the generated Bibtex.
It works previously, see https://github.com/orgs/quarto-dev/discussions/8788#discussioncomment-8534899

Steps to reproduce

---
title: "Document"
date: "2025-01-01"
author: "Author name"
format: html
citation: true
---

Actual behavior

Expected behavior

Has the copy button.

Your environment

• IDE: VSCode 1.105.1
• OS: MacOS Sequoia 15.7.2

Quarto check output

Quarto 1.8.25
[✓] Checking environment information...
      Quarto cache location: /Users/u5537929/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: (not installed)
      Chromium: (not installed)

[✓] Checking LaTeX....................OK
      Using: Installation From Path
      Path: /Library/TeX/texbin
      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: 3.12.2 (Conda)
      Path: /opt/miniconda3/bin/python
      Jupyter: 5.7.2
      Kernels: python3

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

[✓] Checking R installation...........OK
      Version: 4.4.1
      Path: /Library/Frameworks/R.framework/Resources
      LibPaths:
        - /Library/Frameworks/R.framework/Versions/4.4-arm64/Resources/library
      knitr: 1.48
      rmarkdown: 2.28

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

[mcanouil]

Thanks, I can reproduce on current development version.

[AJBogo9]

I ran into this bug too and traced the root cause to src/format/html/format-html-appendix.ts.
The citation appendix template was not updated to use the div.code-copy-outer-scaffold wrapper
that regular code blocks received in 1.8. The CSS hover selector requires this wrapper, so without
it the button icon never appears.

I implemented a fix in my fork at commit 1277b16 and have been daily-driving it locally
on Ubuntu 24.04 and it works correctly. Happy to open a PR if that would help move this forward!