Paper 8 - Fresh-Later Complete-Nonselection Tests: Exact Causal Benchmarks, Identifiability, Selection Robustness, and Decisive Testing

Overview This work presents a practical framework for testing whether an already recorded earlier binary outcome can show a genuine dependence on a newly generated later intervention. The main aim is to separate a potentially meaningful fresh-later effect from ordinary explanations such as postselection, setting-dependent loss, readout effects, hidden-variable ambiguity, incomplete trial inclusion, feedback, or other conventional causal paths. Main Contributions The paper develops and combines: a baseline-independent binary interaction measure based on the quarter-log odds ratio; an exact complete-nonselection benchmark showing that, under definite causal order and a later trace-preserving operation, an already finalized earlier marginal remains unchanged; an exact decomposition of observed interaction into true interaction and selection-induced interaction; a constructive demonstration that postselection can reproduce any strictly positive binary conditional table; a latent-selector model showing why a marginal interaction alone does not uniquely identify an underlying mechanism; independent-calibration methods that can turn an ambiguous fit into a testable forward prediction; sharp symmetric and asymmetric bounds for selection effects; systematic-aware effect-size and sample-size planning rules; and an eleven-gate eligibility framework covering chronology, fresh later choice, complete inclusion, readout stability, nonselection, conventional-path exclusion, inference, contamination control, and replication. Scientific Scope This paper provides a framework for decisive testing, not a claim that a nonstandard fresh-later physical effect has already been observed. Existing experiments are used as design and methodology benchmarks. The mathematical results do not by themselves establish retrocausality, future-to-past signalling, a universal physical law, or a unique microscopic mechanism. Reproducibility The work is supported by QDL Research Suite. All software versions are represented by the Zenodo Concept DOI: 10.5281/zenodo.22952901 Paper 8 was specifically validated using QDL Research Suite v1.7.0, permanently archived at: 10.5281/zenodo.23112372 Included Files Main manuscript PDF Supporting Information PDF SHA256 checksum file for integrity verification Paper 8 DOI: 10.5281/zenodo.23114300