When using a VSCode workspace the JETLS settings are ignored

### Pre-submission checklist

- [x] I have searched [existing issues](https://github.com/aviatesk/JETLS.jl/issues) and confirmed this is not a duplicate.

### Client

VSCode with JETLS version 2026-06-26

### Julia `versioninfo()`

```text
Julia 1.12.6
```

### JETLS version

2026-06-26

### Reproduction with the VSCode reference client

- [x] I have confirmed this issue also reproduces with the VSCode reference client.
- [ ] This issue does NOT reproduce with the VSCode reference client, but I believe JETLS-side changes are needed.

### Description

When using a VSCode workspace, `.JETLSConfig.toml` is ignored

Example:
A file MyWorkspace.code-workspace
```
{
"folders": [
{
"path": "."
},
{
"path": "../SymbolicAWEModels"
},
{
"path": "../VortexStepMethod"
},
{
"path": "../KiteUtils"
}
],
"settings": {}
}
```
In each of the folders I have a file `.JETLSConfig.toml` with the content:
```toml
formatter = "JuliaFormatter"

[full_analysis]
auto_instantiate = false # boolean, default: true

[diagnostic]
all_files = false # boolean, default: true

[[diagnostic.patterns]]
pattern = "not concretized"
match_by = "message"
match_type = "regex"
severity = "off"

[inlay_hint.types]
enabled = false # Hide type hints; keep `end`-tag hints
```

All of them are ignored.

If I open only one of the folders of the workspace it works.

### Steps to reproduce

1. check out two repos from git
2. create a workspace that contains both
3. open the workspace
4. you will see that the `.JETLSConfig.toml` files are ignored

### JETLS configuration (if applicable)

_No response_

### Additional context (optional)

_No response_

Reproduce the problem with MyWorkspace.code-workspace containing multiple folders, each with a .JETLSConfig.toml, then compare it with opening one folder directly. Trace the VSCode extension's workspace and configuration entry point; done means each folder's settings are applied in the multi-root workspace as they are when opened alone.

Written by the indexing model from the issue text.