Constant, ramp, and return offsets now append ordinary channel layers to a lane or cel in explicit owner frames. The inspector exposes the commands as one undoable transaction, shows conflicts, and offers removal or retry while preserving generated bases through regeneration.
Ordered-stack compatibility is shared by validation, conflict reporting, and regeneration, including adjacent replacement coverage. Cel-sheet gaps and headers select their lane, so commands cannot fall through to another column's stale selection.
437 tests, 5,804 assertions; both browser flows; 56 Django tests; optimized frontend build.