Add a full Mozilla Public License v2.0 (LICENSE) and a new ASSETS-LICENSE.md that clarifies Nebula branding, artwork, and other non-code assets are not covered by MPL and are All Rights Reserved unless stated otherwise. Update README.md with a detailed project overview: CEF migration, project status, goals, distribution direction, planned features, architecture notes, build instructions, and explicit licensing guidance separating source code (MPL-2.0) from branding assets and documentation.
