[codex] Fix release gate parity lanes

[midagedev]

Summary

• assign ObjectId values when inserts omit _id, matching MongoDB insert behavior for runtime users
• keep mongos-unpin topology-gated until generated ObjectId differential comparison is explicitly handled
• keep client-bulkWrite-errors* version-gated until its error contract is implemented

Why

The 0.1.9 release-candidate strict Official Suite run found 10 deterministic mismatches: 4 from mongos-unpin generated _id comparison and 6 from client-bulkWrite-errors* suites being admitted by an overly broad lane.

Validation

• .tooling/gradle-8.10.2/bin/gradle test --tests org.jongodb.engine.InMemoryCollectionStoreTest --tests org.jongodb.testkit.UnifiedSpecImporterTest --tests org.jongodb.engine.AggregationPipelineTest
• .tooling/gradle-8.10.2/bin/gradle test --tests org.jongodb.engine.InMemoryCollectionStoreTest --tests org.jongodb.testkit.UnifiedSpecImporterTest
• git diff --check
• .tooling/gradle-8.10.2/bin/gradle clean test

Closes #472

[claude]

APPROVE

요약

Blocking issue 없이 승인합니다. 이 PR은 0.1.9 release-candidate strict Official Suite run에서 발견된 10개 deterministic mismatch를 해결하는 bugfix입니다.

주요 변경 사항

1. Insert _id 자동 할당 (InMemoryCollectionStore.java:141-145)

• _id 필드가 없는 문서에 ObjectId 자동 생성하여 MongoDB insert parity 반영
• Immutable copy 패턴 유지 (source 문서는 수정되지 않음)
• Unit test 추가로 동작 검증

2. Release-gate lane gating (UnifiedSpecImporter.java)

• mongos-unpin 경로를 topology lane override에서 제외
• client-bulkWrite-errors 경로를 version gate에 추가
• 두 변경 모두 conservative: unsupported feature가 supported로 노출되는 것을 방지

판단 근거

• Correctness: _id 자동 생성은 MongoDB 표준 동작에 부합
• Safety: Lane gating 변경은 더 엄격한 기준을 적용 (feature exposure 축소)
• Test coverage: 새 동작에 대한 unit test 존재
• Documentation: CHANGELOG.md 업데이트 포함

_{Reviewed by Z.ai GLM via Claude Code Action}