Color of variable definition hoverbox is missed for embedded language

Does this issue occur when all extensions are disabled?: Yes/No

- VS Code Version: latest (Also tested in the latest commit)
- OS Version: macOS 26.5.2 (25F84)

I will use Vue as the example here. The first picture is an embedded language, which's code snippet has no color, and the second one is normal js/ts file, code snippet has been colored normally.

I've confirmed on my local side it is not a Vue-specific problem. It is because the code here is treated as Vue syntax not TypeScript syntax.

Steps to Reproduce:

1. Install Vue Official extensions
2. Create a `.vue` file, write code like this, press `cmd` and hover the variable `word`, and then you can see the hover box which has problem.

```vue

const word = "Hello"

```