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:_

Riproduci il problema addestrando un modello ML.NET da una procedura guidata .mbconfig e compilando il progetto .NET; esamina il riferimento al progetto generato e il percorso su disco di .mlnet. Il lavoro è completato quando il riferimento generato punta alla posizione effettiva del file e il progetto viene compilato senza dover spostare manualmente il file.

Scritto dal modello di indicizzazione a partire dal testo della issue.