Question, contribution, and scope

The firewall argument concerns the joint compatibility of microscopic unitarity, a near-horizon effective description, and an uneventful horizon for an infalling observer AMPS,Apologia. A resolution must address their interaction in one physical model. Establishing an outgoing spectrum in one model and information recovery in another does not establish that compatibility.

The source records of Cheung separate precisely these obligations. Hawk01-A separates a fixed-background Hawking source from a microscopic message channel CHawk01A. Hawk01-B separates entropy histories from complete code preservation CHawk01B. Hawk02-A requires geometry, complete emission, comparison errors, and complementary leakage to be supplied independently CHawk02A. Em03-C explicitly does not construct an interior algebra CEm03C. Em03-H separates microscopic extraction from a physical infalling-diary interpretation CEm03H.

This manuscript completes a finite-interface mathematical milestone. It does not complete the missing gravitational programme. Its positive construction establishes that an encoded partner, reference-preserving message recovery, and a specified pair test can coexist in one finite model when the partner is not an independent factor of the radiation. Its obstruction results establish that this observation cannot be upgraded to an independent interior copy, or to intervention-independent vacuum statistics.

The distinction is essential. Holographic error correction and entanglement-wedge reconstruction motivate encoded-observable descriptions ADH,DHW,Cotler,Penington. They do not identify the finite construction below with a gravitational interior. Replica-wormhole and island calculations supply further external candidate settings, with their own dynamical and interpretive assumptions AMMZ,PSSY. None is a premise of our finite model. Conversely, the objections in Apologia are not answered merely by renaming an early-radiation observable as an interior observable.