refactor: migrate from Elasticsearch 6.8 to 9.2 and Node 18 to 24

[MrOrz]

Background

rumors-api is migrating from Elasticsearch 6.8 to 9.2 (see cofacts/rumors-api#381). Since this project connects to the same Elasticsearch cluster to export open data, we need to upgrade accordingly.

Changes Required

Dependencies

• Upgrade @elastic/elasticsearch from ^6.8.6 to ^9.x
• Upgrade Node.js engine requirement from >=18 to >=24

Code changes (dumpOpenData.js, dumpUser.js)

• Remove body wrapper from responses: v9 client returns the result directly instead of { body: result }

  // Before
  const { body: result } = await client.search(...)
  // After
  const result = await client.search(...)

• Update hits.total access: v9 returns { value, relation } object instead of a number

  // Before
  result.hits.total
  // After
  result.hits.total.value

Infrastructure

• docker-compose.yml: Upgrade Elasticsearch image from elasticsearch-oss:6.3.2 to elasticsearch:9.2.2, add discovery.type=single-node, remove deprecated ES_JAVA_OPTS
• .github/workflows/ci.yml: Update Elasticsearch service image to 9.2.2, update Node.js version to 24

Reference

• refactor: migrate from Elasticsearch 6.8 to 9.2 and Node 18 to 24 rumors-api#381 — the equivalent migration in rumors-api

[google-labs-jules]

Jules is on it. When finished, you will see another comment and be able to review a PR.

[google-labs-jules]

Ready for a review! A PR has been created.