Development record

The checkoutDigest comment in internal/core/implement/loop/autoplan.go (about lines 181-183) says nothing outside the scratch directory is written but the tree objects write-tree stores, yet its add -A on the scratch index (about line 207) also stores a loose blob for each admitted modified or untracked file, and a configured clean filter may write objects of its own (Git LFS writes under .git/lfs/objects). The indexDigest comment is accurate: it runs only ls-files and write-tree.