- Move Go files from core, e, and runtime directories to the project root.
- Unify package declarations to a single 'core' package.
- Update go.work to exclude the cmd directory from the main build.
- Resolve naming conflicts and update import paths.
- Fix tests to work with the new structure.
Co-authored-by: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>
