Changes touching this path

• the tree writers no longer remove the file they just wrote on a recorded case-only rename: materialize_target and materialize_promoted wrote the target tree and then removed each old path the new tree no longer holds by name, so where the filesystem folds case, as this windows machine and a default macos volume do, the removal took off disk what the write had just put there, and loot undo over such a rename reported pruned 1 path off disk, left the directory empty and made the next status read the recorded path as deleted, which loot move and converge did too, each reproduced by hand with the pre-change binary. both writers now prune through loot_core::disk_entry::prune_unwritten, the one home for the file and directory-entry rule apply-patch has taken since #2007 and #2014: an old path that is the directory entry of a path just written is renamed onto the written spelling, which keeps the bytes and gives the last name component the recorded case, the old name of a hard link is still removed by name, NotFound is a path that was not on disk rather than a path pruned, and any other removal failure is an error naming the path, where materialize_promoted discarded the error and materialize_target counted a failed removal as pruned either way. the identity helpers move out of apply_patch.rs into the new module, drop_empty_parents is shared with the view prune, and the prune makes no filesystem call beyond its removals unless an old path and a written path fold alike. the new pins went red with the entry rule removed (cli 1 passed, 3 failed; core 4 passed, 1 failed), with the old path kept and not renamed (cli 1 passed, 3 failed; core 4 passed, 1 failed) and with the removal error discarded and counted anyway (core 3 passed, 2 failed; the cli pins stay green, since none of them fails a removal). the perf gate dry run reads every counter the same before and after and says no move, ADR 0022 carries the amendment, ADR 0082 section 4 says where the rule lives, CONTEXT.md names it beside the apply-patch rule and in the re-pointing entry, and the workspace suite is green (#2011) de9fb5b0 · dbf3dbe6…

Renames are not followed. loot's tree maps a path to an address, so a rename is a delete and an add. This list is the history of the name, not of the bytes.