Make TP the sole owner of live-buffer text-property publication, mount spans, scoped diff execution, and transaction rollback. Ebox now computes layout owners and retained surface plans, publishes handle/viewport/theme/scroll changes through TP, and keeps its mirrored runtime state transactionally consistent. Remove the former Ebox marker/index/patch executor instead of preserving a second mutation path.\n\nVerification:\n- make ci EMACS=/Applications/Emacs.app/Contents/MacOS/Emacs\n- make package-lint-install EMACS=/Applications/Emacs.app/Contents/MacOS/Emacs\n- strict byte compilation passed for 16 files\n- Ebox production has no tp-- private calls or marker writers\n- TP production has no Ebox dependency