Sekala/Niskala O-Series — Phase B: Admissibility, Stability and Causality. Pre-registered research protocol

Pre-registered protocol for Phase B of the Sekala/Niskala O-series, frozen on 10 November 2026 before any of the work was executed. It fixes the questions, proof obligations (B1-B4), exploratory hypotheses, and success and failure criteria for one problem: whether a nontrivial coupling between a (3,1) spacetime sector and a (1,3) sector with three times can preserve an admissible state space and yield a stable, causally coherent response for one-time observers, without assuming from the start the causality it is meant to explain. The protocol registers a small set of results already established and machine-checked (17 checks in three scripts), treats the scale-dependent permeability of the earlier programme as a target of independent reconstruction rather than an assumption, and separates the perturbative reading of the coupling from the hypothesis that observable spacetime emerges from it. This record contains hypotheses and criteria, not results. Results of the obligations, positive or negative, will be published as separate records citing this one; the protocol is not edited after the freeze, and any correction is issued as a new version with this one preserved. The text was frozen after two independent approvals by AI reviewers under the author's direction; the author is solely responsible for the content. It has not been peer reviewed. Licence: the protocol, reports and records are released under the Creative Commons Attribution 4.0 International licence (CC BY 4.0). The software in the archive (the scripts in scripts/ and verify_freeze.py) is released under the MIT licence. See the files LICENSE and LICENSE-TEXT.md in the archive.