Change LICENSE file

[dblizinski]

Changing license of our extensions from AGPL to Apache

Summary

Licensing layer

• Apache-2.0 extension (3D Slicer, wellness/veterinary module, partner SDK, language binding)
• AGPL-3.0 core (firmware, sensing/beamforming/reconstruction/signal-processing/calibration algorithms, hardware reference design)
• Docs / data / tooling only
• This PR moves a file between the AGPL core and the Apache layer — if checked, this is NOT an ordinary PR: it requires the license-manifest change process (and board approval for anything leaving the core). Link the approval.

Checklist

• Commits are signed off (DCO): git commit -s
• New files carry the correct SPDX-License-Identifier for their layer
• Tests and docs updated
• No incompatible third-party code introduced
• CI is green and CODEOWNERS review requested

Notes for reviewers

[ebrahimebrahim]

Hooray! I will get this integrated, along with its companion PR OpenwaterHealth/SlicerOpenLIFU#655

Are you planning to do the same license change for https://github.com/OpenwaterHealth/openlifu-python ?
And https://github.com/OpenwaterHealth/openlifu-sdk ?
For the sake of SlicerOpenLIFU, it's not too important, because SlicerOpenLIFU does not bundle openlifu-python adn openlifu-sdk -- it rather gives the user the option to install those libraries on their own with a convenient button.

However openlifu-desktop-application does bundle those libraries, and so if those libraries are under AGPL 3 then openlifu-desktop-application inherits that non-permissiveness of AGPL 3.
The desktop application then effectively remains AGPL 3 regardless of whether we change its own license file to apache 2.

That could be completely fine! The one that really benefits from the permissive from the standpoint of open source communities is SlicerOpenLIFU, and that one is fine.

[dblizinski]

I had a question about python and sdk. You answered a portion of the license dilemma: if a bundle inherits an AGPL application, it inherits the non-permissive license. That makes things complicated. So it sounds like both Python and SDK should change to permissive licensing. Which I will do shortly. Thanks