Generated .mlnet file solution reference mismatched from actual location

**System Information (please complete the following information):**
- Model Builder 2022 Version 18.0.0.2615401 (as shown in Installed Extensions List) or 17.19.2.2511501 (as shown in Installed Extension Details -- see _Figure 1_)
- Visual Studio 2026 Version 18.6.1

**Describe the bug**
- On which step of the process did you run into an issue: **Building .NET project** after an MLModel was trained
- Clear description of the problem: **"Could not copy /.mlnet because it does not exist."** After MLBuilder finished training, the resuting `.mlnet` file was saved in `//.mlnet`, but the solution references the file in solution's root folder (`/.mlnet`) instead -- see figures 2 and 3.

**To Reproduce**
Steps to reproduce the behavior:
1. Train an ML.NET model using an `.mbconfig` wizard.
* You will see a reference to "missing file" appear in solution explorer.
2. Attempt to build a project.
* This fails due to the "missing file", well, missing.

**Expected behavior**
The project builds sucessfully.

**Workaround**
Moving the file manually to where the solution is expecting the file fixes the issue without any side effects.

**Figures**
_Figure 1 - mismatched extension version:_

_Figure 2 - project structure with .mbconfig and .mlnet file references:_

_Figure 3 - actual folder structure on disk and in version control:_

_Figure 4 - reference in project after the file is moved on disk to the solution's expected place:_

Reproduziere das Problem, indem du ein ML.NET-Modell aus einem .mbconfig-Assistenten trainierst und das .NET-Projekt erstellst; überprüfe den generierten Projektverweis und den Speicherort von .mlnet auf der Festplatte. Fertig ist die Aufgabe, wenn der generierte Verweis auf den tatsächlichen Dateispeicherort zeigt und das Projekt erstellt wird, ohne die Datei manuell verschieben zu müssen.

Vom Indexierungsmodell aus dem Issue-Text verfasst.