Add MIT License file

[ibourgeois]

Context

As a project maintainer and contributor, I would like to add an MIT License file to clearly define the terms under which this project can be used, modified, and distributed.

Acceptance Criteria

• Create LICENSE file in the root directory
• Include the full MIT License text
• Update copyright year to current year (2026)
• Include correct copyright holder name
• Reference the license in README.md if applicable