visibility-audit: codebook, audit logs and code for an audit of identifier schemas and record linkage in US device surveillance

Codebook and blank judgment templates (fixed 2 September 2026, before any confirmatory judgment), three codebook addenda (3 September 2026), an addendum of 29 September 2026 that states the classification rules for boundary cases (written after classification), the recorded judgments with a documentary audit log of verbatim quotations, field inventories, record-linkage outputs (MDR master-file scan, DEVICE-file join, AccessGUDID results of 2 September 2026) and analysis code for an audit of whether US FDA device surveillance data sources can retrieve adverse events across products that share an upstream component such as a foundation model. The final recorded judgments are in results/final_2026-09-26/. Documentation and data are licensed under CC BY 4.0; code is licensed under the MIT License. Raw FDA files are not redistributed; their download locations and SHA-256 hashes are in data/MANIFEST.md.