- Resolve merge conflicts in CMakeLists.txt, .gitignore, and all src/ files,
keeping the HEAD (native renderer) versions throughout
- Remove stale SDK alternate-tree ref (rexglue-sdk~6e0ca2f) from index
- Drop scratch files: 'New Text Document.txt', *.bak
- Rewrite README with full setup instructions, prereqs table, build
preset table, run command, project layout overview, and Linux section