### Bug description

I have a book with a couple of prefaces : https://resampling-stats.github.io/resampling-with/python-book . I want the chapter numbers to start at the first chapter, so the preface pages are `.unnumbered`.

I want one preface to crossreference the other, but the links are mislabeled in HTML, and fail to resolve in PDF.  Is there a way of doing these crossreferences?

See below for a minimal reproducer.

### Steps to reproduce


```
git clone https://github.com/matthew-brett/test-quarto
cd test-quarto
quarto render .  --to html
```

In the HTML rendering you will see that the crossreferences to the unnumbered prefaces resolve correctly to the page, but get labeled with "Chapter 1" and "Chapter 2", although the contents give no number to the prefaces, and label the first (subsequent) chapter with 2.

For PDF rendering:

```
quarto render . --to pdf
```

I get:

```
WARNING (/Users/mb312/dev_trees/quarto-cli/src/resources/filters/./crossref/refs.lua:110) Unable to resolve crossref @sec-pre1
WARNING (/Users/mb312/dev_trees/quarto-cli/src/resources/filters/./crossref/refs.lua:110) Unable to resolve crossref @sec-pre2
WARNING (/Users/mb312/dev_trees/quarto-cli/src/resources/filters/./crossref/refs.lua:110) Unable to resolve crossref @sec-pre2
WARNING (/Users/mb312/dev_trees/quarto-cli/src/resources/filters/./crossref/refs.lua:110) Unable to resolve crossref @sec-pre1
WARNING (/Users/mb312/dev_trees/quarto-cli/src/resources/filters/./crossref/refs.lua:110) Unable to resolve crossref @sec-pre1
```

and indeed, the references to the preface unnumbered sections appear as e.g. `?@sec-pre1.` etc.

### Expected behavior

The cross-references should resolve to the correct location rather than failing, in the PDF build.

In both cases, the cross-reference label could be the unnumbered document title plus numbering or even section title, as in (in my reproducer) `Preface 2; section 1` or even `Preface 2; Preface 2 subsection`.

### Actual behavior

See above.  Cross-reference to unnumbered sections fails with warning in PDF build.  In HTML build, cross-references point to the correct document and location, but as mislabeled with e.g. "Chapter 1" or "Chapter 2" when the contents give other documents as being chapter 1 and chapter 2.

### Your environment

Macos Ventura 12.4
Latest quarto-cli commit 1f3581304

### Quarto check output

```
$ quarto check 

[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.1.2: OK
      Dart Sass version 1.55.0: OK
      Deno version 1.33.2: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 99.9.9
      Path: /Users/mb312/dev_trees/quarto-cli/package/dist/bin

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

[✓] Checking Python 3 installation....OK
      Version: 3.10.11
      Path: /Users/mb312/.virtualenvs/resampling-with/bin/python3
      Jupyter: 5.3.0
      Kernels: python3, ir

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

[✓] Checking R installation...........OK
      Version: 4.3.0
      Path: /opt/homebrew/Cellar/r/4.3.0_1/lib/R
      LibPaths:
        - /Users/mb312/Library/R/arm64/4.3/library
        - /opt/homebrew/lib/R/4.3/site-library
        - /opt/homebrew/Cellar/r/4.3.0_1/lib/R/library
      knitr: 1.42
      rmarkdown: 2.21

[✓] Checking Knitr engine render......OK
```
cscheid
2023-06-16T11:09:14Z
matthew-brett
enhancement crossref
v1.4
open
Cross-references on unnumbered pages fail (PDF) or are mislabeled (HTML)
https://github.com/quarto-dev/quarto-cli/issues/5946