Code annotation marker is masking content

Bug description

The code annotation marker is masking content unless code-overflow: wrap is used.

This issue is there since at least 1.7, but is likely there since the beginning (not tested earlier version).

Steps to reproduce

---
title: "Code annotation marker is masking content"
format: html
code-annotations: select
---

```{.bash}
# Some comment
# to avoid overlapping copy button and annotation marker
echo "Hello, World!" # <1>
echo "This is a very long line that will not fit on a single line in the document. It should wrap around to the next line automatically, demonstrating how text wrapping works in a Word document generated from Quarto." > long_text.txt # <1>
```

1. This is an annotation.

Actual behavior

Quarto 99.9.9
[✓] Checking environment information...
      Quarto cache location: /Users/mcanouil/Library/Caches/quarto
[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.6.3: OK
      Dart Sass version 1.87.0: OK
      NOTE: Deno version 2.4.5 does not strictly match 2.3.1 and strict checking is enabled. Please use 2.3.1.
      Typst version 0.13.0: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 99.9.9
      commit: e858bba000cc35277bdb8911d6ad86ccc74e6552
      Path: /Users/mcanouil/Projects/quarto-dev/quarto-cli/package/dist/bin

[✓] Checking tools....................OK
      TinyTeX: v2025.08.02
      Chromium: (not installed)

[✓] Checking LaTeX....................OK
      Using: TinyTex
      Path: /Users/mcanouil/Library/TinyTeX/bin/universal-darwin
      Version: 2025

[✓] Checking Chrome Headless....................OK
      Using: Chrome found on system
      Path: /Applications/Brave Browser.app/Contents/MacOS/Brave Browser
      Source: QUARTO_CHROMIUM

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

[✓] Checking Python 3 installation....OK
      Version: 3.13.2
      Path: /Users/mcanouil/Projects/quarto-dev/quarto-playground/.venv/bin/python3
      Jupyter: 5.8.1
      Kernels: julia-1.11, uv, python3

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

(\) Checking R installation...........ℹ R version 4.5.1 (2025-06-13)
! Config '~/.Rprofile' was loaded!
[✓] Checking R installation...........OK
      Version: 4.5.1
      Path: /Library/Frameworks/R.framework/Resources
      LibPaths:
        - /Users/mcanouil/Projects/quarto-dev/quarto-playground/renv/library/macos/R-4.5/aarch64-apple-darwin20
        - /Users/mcanouil/Library/Caches/org.R-project.R/R/renv/sandbox/macos/R-4.5/aarch64-apple-darwin20/4cd76b74
      knitr: 1.50
      rmarkdown: 2.29

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

Start by rendering the provided Quarto document with code-annotations: select and compare it with the same example using code-overflow: wrap. Trace the code-annotation rendering path responsible for the marker and add a regression test covering a long annotated line; done means the marker no longer masks content without requiring wrapping.