Page title is not interpolated inside <title> element

[paul-louyot]

Describe the bug

When the title of a page is the result of variable interpolation, it shows correctly inside a h1 element, but the value of the variable does not end up inside the <title> element of the rendered HTML page.

Let's say I have this inside example.md of the starter template:

<script setup>
const title = "VitePress 💙 StackBlitz"
</script>

# {{ title }}

Then the title element will contain {{ title }} | VitePress

Reproduction

https://stackblitz.com/edit/vite-pivzggyp?file=docs%2Fexample.md

Expected behavior

The title element contains the value of the variable, e.g VitePress 💙 StackBlitz | VitePress

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 18.20.3 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.2.3 - /usr/local/bin/npm
    pnpm: 8.15.6 - /usr/local/bin/pnpm
  npmPackages:
    vitepress: latest => 1.6.3

Additional context

Validations

• Check if you're on the latest VitePress version.
• Follow our Code of Conduct
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.

[Tynopia]

Hi, I also reported this yesterday. With my PR, you can skip the old logic and use the compile function to generate the compiled title.

Issue: #4637
PR: #4630