LayerForge v9: Phase 2b Verification Update — Two-Layer Fidelity Structure and Hybrid Ensemble Path

Supplementary deposit for LayerForge v9 (Phase 2b Verification Update). Includes the v9 main paper PDF, appendix PDF, 3-round peer review history (Reviewer Agent / Author Agent loop, Accept), public verification index, and 22 raw JSON output files sufficient for independent re-verification of the paper's numeric claims (p-values, comp_mean, accuracy). Core contributions of v9: Two-layer fidelity structure (theme-level semantic PASS / fact-level lexical FAIL) corroborated by multiple metric families on two datasets (hotpotqa EN, livedoor JA). Statistically significant Hybrid ensemble path (LayerForge + K-means): hotpotqa N=100 p=2.7e-05, livedoor N=27 p=5.1e-08 (paired t-test, ensemble vs LayerForge alone). Baseline parameter values frozen under bounded ablation budget (14 ablations, tested N=5-30, no parameter change reached the IMPROVEMENT-LARGE threshold). Explicit extrapolation boundaries per pattern coverage. The v8.1 core algorithm is unchanged in v9; this update adds verification depth and an evidence-grounded improvement direction (Hybrid ensemble) without modifying the v8.1 spec. Self-preference bias disclosure: The v9 paper was drafted with Claude Code assistance, and the 3-round peer review loop was conducted by Claude Code subagents (same model family). Per Anthropic's LLM-as-judge guidance, formal acceptance evidence requires cross-check by either (a) a human reviewer, (b) a different LLM family (GPT-4 / Gemini / Mistral), or (c) Anthropic API direct + Haiku 4.5. This deposit's verification_results/ contains only the metric-only subset (22 JSON files of the 27 total verifications cited in the paper). Driver scripts and per-record verification narratives (ADR-022 Sections 1-8 format) are maintained in a separate author-maintained repository, currently private during pre-publication review, available to peer reviewers on request from the corresponding author. Note on versioning: The paper itself is titled "LayerForge v9" (= the author's internal version corresponding to the Phase 2b verification update of the v8.1 published baseline). In Zenodo's version system this is registered as Version 1.1 (minor update of the v8.1 baseline deposit, Zenodo Version 1.0, DOI 10.5281/zenodo.19651035).