[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Superseded by consolidated postal geocoding PR #124.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.

---

Summary

Add full five-digit KOR postal coordinate lookup for approximate return-distance analysis.

GeoNames KR.zip (35,583 rows)
  → unique coordinate pairs per postal code
  → unweighted mean (34,249 representative points)
  → existing coordinates('KOR', postcode) lookup

Source: https://download.geonames.org/export/zip/KR.zip, retrieved 2026-11-04; archive member dated 2026-11-04. GeoNames CC BY 4.0 attribution and source checksum are in docs/geocode-KOR.md. This is not an official Korea Post extract. National completeness and distance error bounds are unverified. Points are representatives, not measured postal centroids. Duplicate source rows do not add weight.

Evidence

• Before: KOR returned undefined because it was not in the geocode allowlist.
• After: coordinates('KOR', '04524') returns ['126.9777', '37.5662']; missing codes still return undefined. Existing normalization, coordinate string type, exports and other countries remain unchanged.
• Offline tests cover urban/rural/island points, leading zeros, duplicate-point aggregation, misses, uniqueness and finite coordinate ranges. Source notes link primary checks for Seoul, rural Jeju and Dokdo.
• Passed: npm test (99 tests), npm run lint, npm run format:check, npm run validate:data; generator assertions also passed.

Merge Danger

Door: two-way

Blast Radius: KOR

Adds one geocode allowlist entry plus KOR data, tests, generator and source notes. lib/geocode.js may overlap with other country PRs. No dependencies, generic normalization changes, fraud decisions, publication or deployment. Do not merge as part of this task.

[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 2026-11-04T22:03:48.020209Z	1745dd6	PR opened

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.