419ddea52a
Update the upstream merge script to identify and link to the previous compatibility commit. This ensures that pre-merge transformations maintain a proper commit history by using multiple parents when a prior compatibility base is found, rather than creating disconnected commits. - Add `findLatestCompatCommit` to locate previous compatibility commits - Implement `commitTree` and `updateBranch` for low-level git manipulation - Update `merge.ts` to integrate compatibility base detection and multi-parent commits