mne_align: fix alias forward declarations for AcquiredPoints and PolhemusConnection

[chdinh]

Summary

Fixes C++ type conflicts in mne_align caused by forward-declaring alias types as classes.

Changes

• Include acquired_points wrapper where AcquiredPoints is used and remove invalid class forward declarations.
• Include polhemus_connection wrapper where PolhemusConnection is used and remove invalid class forward declarations.

Validation

• cmake --build build/developer-dynamic -j8 succeeds locally.
• Full ctest run was executed; multiple unrelated runtime failures remain in this environment.

[Copilot]

Pull request overview

This PR fixes C++ type conflicts in mne_align by removing invalid class forward declarations for types that are actually aliases (AcquiredPoints, PolhemusConnection) and instead including the local thin forwarding headers that define those aliases.

Changes:

• Add acquired_points.h include where AcquiredPoints is referenced and remove invalid forward declarations.
• Add polhemus_connection.h include where PolhemusConnection is referenced and remove invalid forward declarations.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
src/applications/mne_align/mne_align.h	Includes the forwarding headers for AcquiredPoints/PolhemusConnection and removes invalid forward declarations to resolve alias/type conflicts.
src/applications/mne_align/align_wizard.h	Includes the forwarding header for PolhemusConnection and removes the invalid forward declaration.
src/applications/mne_align/align_3d_view.h	Includes the forwarding header for AcquiredPoints and removes the invalid forward declaration.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.