C2 algebra and gravitational response: Exact survival obstruction, local dictionary certificates, and continuum tests

We report an exact obstruction to complete original-active survival in the inherited C2 algebraic model and a separate constructive result for a conditional spatial field model. The native discarded-component matrix has rational rank 670; together with the certified rank-24 projection this gives original-active dimension 694. Restricted AB/AH sectors admit strict actions and equivariant splittings, but an explicit nonzero original-active vector is also a defining composition defect. It therefore vanishes in the correction quotient, ruling out full recovery of the unchanged original-active space. This negative result does not invalidate the restricted splittings or exclude gravity on a different construction. For a separately specified enlarged contact-field model over a three-variable Laurent ring, we reconstruct an exact null column and verify a contact-only equivariant left inverse for both declared value types. This produces local dictionaries satisfying the single-column equation for every target in the ring, with equivariance when the target has the required transformation law. It does not select a physical dictionary or establish temporal dynamics. We retain the continuum strain, curvature, source-response and observational calculations as conditional benchmarks, and replace the former full-survival roadmap with explicit revised algebraic and physical questions. Locally retained source records and executable checks distinguish replayed native evidence, newly checked spatial identities and unproved physical correspondences. This PDF-only release does not deposit those underlying artifacts. No Einstein limit, Newton constant, universal matter coupling or full gravitational gauge system is derived. Major revision, version 2.0. Supersedes the algebraic open-status account in version 1.1 and incorporates the landed G47 re-correction. This public deposit contains the revised manuscript PDF only. Data availability. The manuscript source, internal review records, finite native witness, exact spatial dictionary coefficients and executable verification materials are retained locally by the author and are not deposited with this version. The PDF states the mathematical arguments and the limits of the reported computations. Scope. No physical action, temporal completion, universal matter coupling, full C2 closure or Einstein limit is claimed.