What is new in the adaptation

The analytical results above reproduce and reorganize the mechanisms of V@1 CheungV. The operational extension is the explicit form-compression bridge: a symmetric cubic form, without an unproved self-adjoint continuum generator, still defines an exact finite instrument after its finite carrier has been declared. The joint form estimate then controls that fixed compressed instrument.

The cubic qubit makes the bridge nonvacuous. It also demonstrates why agreement of lower-degree data cannot be promoted to agreement of the cubic scalar response.

This is a scoped contribution, not a priority claim about all finite compressions or measurement theory.