Book: chapters specified with with `./` in their path fail crossref resolution

Bug description

What I did...
In a Quarto Book project edited by plaintext editor and compiled to HTML (web page) at the command line, I created a document with several figures and subsequently crossref'd them using the @fig-id notation.

What happened...

• Instead of showing up as an auto-numbered "Figure 1", "Figure 2", etc., the crossrefs are listed as "Figure fig-id". The label "Figure" was added by Quarto, but the fig-id is not being resolved to the number.
• A crossref to a fake figure (e.g., @fig-fake-name-that-doesnt-exist) displays in the same way, as "Figure fig-fake-name-that-doesnt-exist") -- without the ? that usually precedes an unknown crossref.

What I expected to happen...

• Correct crossrefs should display with the figure label followed by the auto-number, e.g. "Figure 1", "Figure 2", etc.
• A crossref to a non-existent fig-id should display a question mark in front of the figure, as happens with bibliographic citations; e.g., "Figure ?fig-fake-name-that-doesnt-exist".

Steps to reproduce

# Bugs

## Figure crossref not working

Consider these figures:

![A simple image](_figures/figure_xkcd_1987.png){#fig-simple-image width=250}


::: {#fig-image-within-div}
![](_figures/figure_xkcd_353.png){width=250}

An image within a DIV
:::

```{python}
#| label: fig-python-code-chunk
#| fig-cap: "Figure generated by running a code chunk."
#| echo: true

import numpy as np
import matplotlib.pyplot as plt

r = np.arange(0, 2, 0.01)
theta = 2 * np.pi * r
fig, ax = plt.subplots(
  subplot_kw = {'projection': 'polar'} 
)
ax.plot(theta, r)
ax.set_rticks([0.5, 1, 1.5, 2])
ax.grid(True)
plt.show()
```

::: {#fig-python-code-chunk-within-div width=150}

```{python}
#| echo: true

import numpy as np
import matplotlib.pyplot as plt

r = np.arange(0, 2, 0.01)
theta = 2 * np.pi * r
fig, ax = plt.subplots(
  subplot_kw = {'projection': 'polar'} 
)
ax.plot(theta, r)
ax.set_rticks([0.5, 1, 1.5, 2])
ax.grid(True)
plt.show()
```
Figure generated from running a code chunk within a DIV.
:::

Now we will try to crossref each of them:

- @fig-simple-image -- should be "Figure 1"
- @fig-image-within-div -- should be "Figure 2"
- @fig-python-code-chunk -- should be "Figure 3"
- @fig-python-code-chunk-within-div -- should be "Figure 4"
- @fig-fake-figure-id -- should not resolve because there is no such figure id.


Fin.

Expected behavior

• Correct crossrefs should display with the figure label followed by the auto-number, e.g. "Figure 1", "Figure 2", etc. If chapters: true is set in the crossref: section of _quarto.yml, then the figure numbers should be prefixed by the chapter, e.g. "Figure 1.1" for Chapter 1 or "Figure H.1" for Appendix H.
• A crossref to a non-existent fig-id should display a question mark in front of the figure, as happens with bibliographic citations; e.g., "Figure ?fig-fake-name-that-doesnt-exist".

Actual behavior

• All figures did display correctly.
• All figure captions did display correctly immediately below the figures -- They do appear as "Figure 1: A simple image", "Figure 2: An image within a DIV", "Figure 3: Figure generated by running a code chunk.", and "Figure 4: Figure generated from running a code chunk within a DIV."
• The crossref displays incorrectly -- Instead of showing up as an auto-numbered "Figure 1", "Figure 2", etc., the crossrefs are listed as "Figure fig-id". The label "Figure" was added by Quarto, but the fig-id is not being resolved to the number.
• No '?' appears prefixing a crossref to an invalid fig-id -- With a crossref to a fake figure (e.g., @fig-fake-name-that-doesnt-exist) displays in the same way, as "Figure fig-fake-name-that-doesnt-exist" rather than "Figure ?fig-fake-name-that-doesnt-exist".
• The error occurs no matter what kind of figure embedding I use: simple image, an image within a div, programmatic plotting from a code chunk, programmatic plotting from a code chunk contained within a div, etc.

Specific to this sample document, this is what I see as the crossref output:

• Figure fig-simple-image – should be “Figure 1”
• Figure fig-image-within-div – should be “Figure 2”
• Figure fig-python-code-chunk – should be “Figure 3”
• Figure fig-python-code-chunk-within-div – should be “Figure 4”
• Figure fig-fake-figure-id – should not resolve because there is no such figure id.

I will paste a screencap below.

It is noteworthy that this problem only occurs in HTML (web page output). The PDF rendering generates correct figure crossrefs.

Your environment

• macOS Sonoma 14.3
• Quarto 1.4.553 and pre-release 1.5.28 -- both produce the same result
• Plaintext workflow with quarto preview or quarto render at command line

Quarto check output

quarto check

Quarto 1.5.28
[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.1.11: OK
      Dart Sass version 1.70.0: OK
      Deno version 1.41.0: OK
      Typst version 0.10.0: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 1.5.28
      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 basic markdown render....OK

[✓] Checking Python 3 installation....OK
      Version: 3.11.8 (Conda)
      Path: /Applications/miniconda3/envs/quarto/bin/python
      Jupyter: 5.7.1
      Kernels: python3

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

[✓] Checking R installation...........OK
      Version: 4.2.3
      Path: /Library/Frameworks/R.framework/Resources
      LibPaths:
        - /Library/Frameworks/R.framework/Versions/4.2-arm64/Resources/library
      knitr: 1.42
      rmarkdown: 2.21

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