Normalize size units and intrinsic sizing across Elisp and native layout. Add help, pointer, hover-style and keymap support with reusable interaction adapters.
Keep content updates local, preserve scroll caches and hover borders, and avoid rebuilding retained plans and ownership metadata for stable geometry.
Validation: make check and native-rust-tests passed; targeted native interaction and scroll publication regressions passed.
Expose detached committed snapshots and explicit canonical construction ownership. Preserve scoped publication and rollback, share Box decoration, and reuse completed Flex/Grid work only under proven constraints.
