[jkrenge]

Superseded by consolidated postal geocoding PR #124. This PR's head commit is retained in the combined branch. Combined CI passes on Node.js 24/26 and static checks.

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Summary

CZE previously returned undefined for every postcode. Add approximate full-postcode lookup for return-location distance analysis. The October 2026 parcelLab analysis observed 42,205 provider-coded return tracking records with destination country CZE; this is observed parcelLab volume, not national market share.

CZE postcode (11000 or 110 00)
  → CZE-only normalization
  → representative point [longitude, latitude] as strings

Add 2,694 unique five-digit postcode records from 15,507 GeoNames locality rows. Source: https://download.geonames.org/export/zip/CZ.zip, retrieved 2026-11-04; export timestamp 2026-11-04 03:53 CET, CC BY 4.0 with attribution. Use the unweighted mean of distinct coordinate pairs per code; duplicate source rows do not add weight. See docs/geocode-CZE.md for source hash, reproduction, primary Czech Post checks, and limits.

Evidence

• Before: coordinates('CZE', '110 00') returned undefined.
• After: returns ['14.425633', '50.084633']; compact/spaced input, existing country aliases, and all 2,694 output lookups have offline tests.
• Generator tests cover duplicate independence, row-order independence, and invalid coordinates.
• npm test, npm run lint, npm run format:check, and npm run validate:data pass. Data validation retains two known AUT/BEL warnings.
• No region mappings or lib/region.js changes. Other-country behavior and string return values are preserved.

Merge Danger

Door: two-way

Blast Radius: CZE

Source coverage is partial/unverified against a national inventory. Points are locality estimates, not postal-area centroids or scan-site locations; rural errors can be kilometres. No national accuracy bound is available. Six decimal places do not establish accuracy. Primary checks confirm urban/rural/border postcode-locality associations, not postcode-wide coordinate accuracy.

Shared-file overlap with concurrent country PRs is limited to lib/geocode.js (allowlist and normalization). This PR does not merge, publish, or deploy the package.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-11-04T22:19:05.908116Z	5b7a754	PR opened

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