Mermaid / .mmd broken

[adrian-awesome]

Describe the bug
Files with an .mmd (Mermaid Markdown) extension complete freeze the application. This happens with or without a specific .mmd extension (such as https://marketplace.visualstudio.com/items?itemName=bierner.markdown-mermaid)

Please confirm that this problem is VSCodium-specific

• This bug doesn't happen if I use Microsoft's Visual Studio Code. It only happens in VSCodium.

Please confirm that the issue/resolution isn't already documented

• I checked the Docs page and the Troubleshooting page and my issue is not mentioned there.

To Reproduce
Steps to reproduce the behavior:

1. Open an .mmd file
2. Try to click on anything
3. See the beachball

Expected behavior
The file should open with editor capabilities such as an .md file would be. With the appropriate extension installed, it should also be able to open a preview of the diagram

Desktop (please complete the following information):

• OS: macOS Sequoia 15.3.2
• Architecture: arm64
• Version: 1.98.2.25078
• App Manager: Homebrew
• Sandboxed: No

Additional context
At first I thought this was an issue with the extension, but even after removing all .mmd associated extensions and purging the cache, the issue remains.

[daiyam]

I don't have any freeze when opening a .mmd like:

```mermaid
graph TD;
    A-->B;
    A-->C;
    B-->D;
    C-->D;
```

The markdown preview works fine (with .md). I already had it installed.