Conclusion

A destructive measurement primitive fixes an output signature, not a geometric observation policy. The latter must declare coupling observables, control, resource checks, locations, and accessible residual outputs.

With those declarations in place, arbitrary spectator extensions preserve geometry and accessible reductions under spectator-blind control. Restricted coherent deferral reproduces destructive readout on the common record–matter interface. Record compatibility is exactly an effect pullback, with an exact unassisted event-norm error. Residual compatibility is stronger: for sharp readouts and a coarse Lüders instrument, its remaining obstruction is intra-outcome coherence. Continuations preserve observation boundaries precisely when their adjoints preserve the declared observable spaces.

The four-face certificate realizes one discrete geometric event on a prescribed slicing of a fixed spacetime, including its boundary, guard, transport, and finite reversible code. It neither derives geometry from measurement nor changes the ambient gravitational solution.

The observation-boundary problem is closed within the stated finite model. The distributional graph problem and gravitational dynamics remain separate tasks.