flowchart TD SOURCE[(Private inspection histories
read-only source)] SAMPLE[Private page-sampled histories
up to 10,000 vehicles
keyed vehicle tokens] SOURCE -->|read-only bounded export| SAMPLE SAMPLE --> STAGE[Normalize labels
deduplicate and validate] STAGE --> EPISODES[Build 30-day episodes
first attempt is the target] EPISODES --> MART[Point-in-time feature mart
returning vehicles only] subgraph SPLITS[Private development chronology] direction LR CONTEXT[2010-15
history context] TRAIN[2016-22
train] TUNE[2023
tune] CAL[2024
calibrate] HOLDOUT[2025
one-time holdout] SHADOW[2026 partial
shadow context] end MART -.-> SPLITS MART --> LOGISTIC[Regularized logistic + Platt
final prototype model] MART --> TREE[Histogram gradient boosting + Platt
benchmark only] LOGISTIC --> PRIVATE[Private model artifacts
manifests, checksums, metrics] TREE --> PRIVATE HOLDOUT -.-> REPORT[Private/report-only
one-time comparison] PRIVATE -.-> REPORT MART --> EXPORT[Aggregate, suppress,
round, validate] PRIVATE -.->|pre-2025 diagnostics only| EXPORT subgraph PUBLIC[dashboard/public/data - public boundary] direction TB MANIFEST[data_manifest.json] OVERVIEW[overview_period_county.json] COHORTS[cohort_scorecard.json] AGE[age_risk_curve.json] COVERAGE[coverage_quality.json] FILTERS[filter_catalog.json] DIAGNOSTICS[model_diagnostics.json] HASHES[sha256_manifest.json] end EXPORT --> PUBLIC PUBLIC --> CONTRACT[Fail-closed browser validation] CONTRACT --> SITE[Static dashboard
semantic HTML + CSS
vanilla ES modules + inline SVG] subgraph VIEWS[Presentation-ready views] direction TB V1[Overview] V2[Sample cohorts] V3[Model & benchmark] V4[Data & methods] end SITE --> VIEWS subgraph GUARDRAILS[Publication guardrails] direction TB G1[Private 10,000-vehicle sample
not population estimates] G2[Minimum episode, vehicle,
and binary-class support] G3[No identifiers, raw/operational rows,
credentials, or row-level predictions] G4[No county population rankings
or vehicle-level prediction service] end EXPORT -.-> GUARDRAILS SITE --> DEMO[Allowlisted local static server
same-network live demo] subgraph TESTS[Verification] direction LR PY[Python pipeline/model/export tests] JS[Node dashboard contract tests] end MART -.-> PY PUBLIC -.-> JS classDef private fill:#fff3e0,stroke:#b45309,color:#3b2415 classDef model fill:#e0f2fe,stroke:#0369a1,color:#0c4a6e classDef public fill:#ecfdf5,stroke:#047857,color:#064e3b classDef warning fill:#fef2f2,stroke:#b91c1c,color:#7f1d1d class SOURCE,SAMPLE,STAGE,EPISODES,MART,PRIVATE,REPORT private class LOGISTIC,TREE model class PUBLIC,CONTRACT,SITE,VIEWS,DEMO public class GUARDRAILS warning