Implement TUI search and mutation workflows

docs/tree-mutations.md

@@ -29,6 +29,12 @@ The commit callback must report failure only when it has not created a commit;
 it receives the compatible intent `Remove ... from store.`, `Rename ... to
 ....`, or `Copy ... to ....`.
 
+`MutationOutcome` also returns a typed post-operation selection for transfers,
+identifying the actual destination entry or directory after container
+semantics have been applied. Presentation layers use this result to refresh
+selection without reimplementing path or destination rules. Removals omit a
+target so a refreshed tree can retain the nearest surviving row.
+
 Compatibility tests materialize the shared upstream-format fixtures and cover
 entry and subtree mutations, recursive requirements, cancellation, forced
 overwrite, directory destinations, ambiguity, nested signed recipient