Probabilistic Drift Geometry Under Declared Constraint

Post-Horizon Instrumental Lineage — 4 August 2026 This record forms part of the Post-Horizon Instrumental Lineage of the Architecture of Limitation research programme. The designation and conditions governing subsequent review are established in K1 Open Concordance Phase: A Structured Validation and Evidence-Alignment Programme for the Open Research Release of AoLOS, v1.0, 2 August 2026, doi:10.5281/zenodo.21758275. The record is retained unchanged as evidence of the conditions, tools, concepts, and architectural pressures through which the programme developed. Inclusion in this lineage does not imply retrospective K1 validation or completion of article-level concordance; any proposition-specific qualification, reanalysis, companion publication, or unresolved pressure will be recorded separately through the phase’s declared review process. -- This study introduces repeated-run probabilistic drift analysis under invariant artifact and contract conditions across three configuration states within a single kernel lineage: instrumented restraint (K0 + K0G-M), measurement-only instrumentation (K0G-M), and instrumental governance (K0G). Fifteen independent runs were executed and aggregated within an Operational Boundary Metrics (OBM) measurement surface. Results demonstrate that probabilistic drift geometry is configuration-sensitive. Instrumented restraint produces the smallest dispersion envelope. Measurement-only states expose maximal structured variance. Governance produces state-dependent compression relative to elevated dispersion but does not compress below the instrumented restraint baseline (K0 + K0G-M). These findings are descriptive and confined to the declared artifact and measurement grammar. The paper formalizes probabilistic drift geometry as a structured object consisting of dispersion magnitude, layer concentration, regime stability, deviation-set coherence, and interaction curvature across configurations. The contribution is methodological rather than prescriptive: architectural configuration measurably alters the probabilistic envelope of inference under invariant conditions. Transparency of boundary logic, instrumentation state, and governance activation becomes empirically relevant under configuration-sensitive drift. No normative ranking or task-class mapping is proposed. This work belongs to the Architecture of Limitation research program.