VSCode Extension does not open target of `detailed-architecture` reference in CALM Node

## Bug Report

### Steps to Reproduce:
1. open `calm/architecture/calm-3.json`.
2. Run `CALM: Open Preview`, go to the **Docify** preview, and click the `CALM Hub API` node, which has `details.detailed-architecture` set to `calm-hub-detail.architecture.json`.
3. When clicking on CALM model elements tree structure in navigation panel, the `CALM Hub API` view from `calm-3.json` is shown, not `calm-hub-detail.architecture.json`.

### Expected Result:
Clicking `CALM Hub API` should open `calm/architecture/calm-hub-detail.architecture.json`, and the VS Code extension preview should retarget to the detailed architecture document.

### Actual Result:
The preview stays focused on `calm-3.json` and only re-shows the current parent architecture instead of displaying the `detailed-architecture` target document. The child architecture is not shown in the preview after the click.

No exception or stack trace was observed for the original bug behavior. The issue presents as incorrect navigation/preview behavior rather than a thrown error.

### Environment:
- VSCode: 131.0
- VS Code extension: `calm-vscode-plugin` version `0.6.0`. The issue also shows up with the `0.7.0` version that is in the repo but not released.
- OS: macOS 15.7.7
- Runtime:
- v26.3.1 (npm v11.16.0)

### Additional Context:
Used the [VSCode Extenstion Multi-Document Navigation](https://calm.finos.org/working-with-calm/vscode-extension#multi-document-navigation) as basis for this test.

I assume URL and file references in `details.detailed-architecture` are valid.

The issue is specifically about node-level `details.detailed-architecture` navigation from the VS Code extension preview. In `calm/architecture/calm-3.json`, the `CALM Hub API` node points to `calm-hub-detail.architecture.json`, but clicking that node in the Docify preview reselects or rerenders the parent document instead of navigating to the child document.

A last note, use of `details.detailed-architecture` in timeline moment navigation works as expected, i.e., displays the referenced file. I was expecting the same behavior when `details.detailed-architecture` is in a CALM json file.

Here is video demonstrating the issue (Turn on sound to hear narration):

https://github.com/user-attachments/assets/5a720dcd-2e40-47f7-8c7b-da066ec0b4f0

State of my local repo where the issue surfaces.
```
$ git log -n 5 --oneline
25be3b52 (HEAD -> main, upstream/main, upstream/HEAD, origin/main, origin/HEAD) fix: resolve open CodeQL code scanning alerts (75-79) (#2919)
4dbb561e docs: embed live CALM architecture diagram via @finos/calm-docusaurus-plugin (#2909)
0852651a Merge pull request #2917 from rocketstack-matt/fix/security-deps-npm-2026-07-30
7c06bf40 chore(deps): patch npm brace-expansion DoS across all resolved major lines
```

Start at the CALM: Open Preview Docify navigation flow, using calm/architecture/calm-3.json and calm-hub-detail.architecture.json to trace how node-level details.detailed-architecture references are handled. Compare this with timeline moment navigation, which already opens the referenced file. Done means clicking CALM Hub API retargets the preview to the child architecture document rather than reselecting the parent.

Written by the indexing model from the issue text.