feat(postcodes/VN): bulk-import 63 Vietnam province postcodes via VNPost (#1039)

[dr5hn]

Summary

Adds 63 Vietnam province-level postcodes parsed from the
navuitag/dvhcvn MySQL dump.

• Coverage: country-only by design.
• Granularity: one record per pre-2024 province with VNPost's
  6-digit code.

Why country-only

Vietnam's 2024-2025 administrative restructuring merged the source's
63 pre-2024 provinces into the post-merger 34 provinces represented
in CSC's states.json. A clean per-row state FK is no longer
possible from this dataset — matches the SE/SI/ZA/GR precedent.

Source & licence

• Source URL: https://raw.githubusercontent.com/navuitag/dvhcvn/master/database/database.sql
• Origin: VNPost publicly published province codes redistributed by
  navuitag.
• Each row: "source": "vnpost-via-navuitag"

Validation

• python3 -m py_compile clean.
• 100% of 63 codes match country.postal_code_regex (^(\d{6})$).
• No auto-managed fields (id, created_at, updated_at, flag).

Test plan

• Importer compiles and runs on a clean checkout.
• Cross-reference validator passes (regex + country FK).
• Idempotent merge verified.
• CI pipeline green.

Refs #1039.

🤖 Generated with Claude Code

[github-actions]

CSC Validation Report

PR Format

• ✅ Description provided
• ✅ Data source linked
• ✅ Issue linked (recommended for data changes)
• ✅ Justification / context provided

Labels applied: data:postcodes

Schema Validation (63 records)

✅ All records passed validation

Cross-Reference Validation

✅ 63 reference(s) verified

Source URL Verification

✅ 2 source URL(s) accessible

---

✅ All checks passed | Status: Ready for review

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds province-level Vietnam postcodes (VNPost) to the contributions dataset and includes a script to (re)generate the JSON from the upstream navuitag/dvhcvn SQL dump.

Changes:

• Added contributions/postcodes/VN.json containing 63 province-level postcode records.
• Added bin/scripts/sync/import_vietnam_postcodes.py to fetch/parse the upstream SQL and write VN.json idempotently.

Reviewed changes

Copilot reviewed 1 out of 2 changed files in this pull request and generated 2 comments.

File	Description
contributions/postcodes/VN.json	New Vietnam postcode dataset (country-only, province-level).
bin/scripts/sync/import_vietnam_postcodes.py	New importer script to generate/merge VN.json from upstream SQL.

[Copilot]

There are duplicate postcodes assigned to different locality_name values (e.g., 390000 appears for both Lai Châu and Điện Biên). If consumers expect a unique mapping between province and postcode, this creates ambiguity and likely indicates an incorrect import/result. Recommend verifying the upstream values and correcting the conflicting entries, and/or enforcing a validation step in the importer that fails when the same code is emitted for multiple distinct provinces (unless duplicates are explicitly intended and documented).

[Copilot]

Another postcode duplication: 790000 is assigned to both Bà Rịa - Vũng Tàu and Bắc Ninh. Same concern as above—this likely breaks lookups keyed by code and suggests at least one of these rows is wrong. Please validate against the source and fix the conflicting code(s); consider adding an importer-side check to detect and error on duplicated code values across distinct locality_names.