docs: 빌드·CI 감사 계획과 진행 중이던 문서 정리

- CI 단계 분리 계획 추가 (docs/superpowers/plans/2026-09-16-ci-stage-separation.md).
  빌드·CI 레이어 전수 리뷰 133건의 결론과 Track A/B/C 작업 순서를 담는다.
- public-path 보안 기준선을 실제 배포 기본값(/v1/healthcheck)으로 재생성.
  이전 값은 gitignore 된 src/.env 에서 유래해 재현이 불가능했다.
- 진행 중이던 ADR·리뷰·테스트 전략 문서 반영, 대체된 grpc 계획 문서 제거.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

docs/superpowers/plans/2026-07-28-messaging-first-r2-polling-producer.md

@@ -2899,12 +2899,12 @@ authority and destructive downgrade are forbidden.
       dev.caskeleton.adapter.outbound.persistence.outbox.OutboxClaimRepository
       dev.caskeleton.adapter.outbound.persistence.postgresql.PostgreSqlOutboxClaimRepository
       dev.caskeleton.adapter.outbound.persistence.outbox.OutboxReaper
-      dev.caskeleton.bootstrap.outbox.OutboxLeaderElectionToken
-      dev.caskeleton.bootstrap.outbox.OutboxLegacyToV2CutoverCoordinator
-      dev.caskeleton.bootstrap.outbox.OutboxLegacyPreCommitRecoveryCoordinator
-      dev.caskeleton.bootstrap.outbox.LegacyOutboxRelayControlAdapter
-      dev.caskeleton.bootstrap.outbox.MessagingAuthorityCutoverJobSettings
-      dev.caskeleton.bootstrap.outbox.MessagingAuthorityCutoverApplicationRunner
+      dev.caskeleton.bootstrap.autoconfigure.outbox.OutboxLeaderElectionToken
+      dev.caskeleton.bootstrap.autoconfigure.outbox.OutboxLegacyToV2CutoverCoordinator
+      dev.caskeleton.bootstrap.autoconfigure.outbox.OutboxLegacyPreCommitRecoveryCoordinator
+      dev.caskeleton.bootstrap.autoconfigure.outbox.LegacyOutboxRelayControlAdapter
+      dev.caskeleton.bootstrap.autoconfigure.outbox.MessagingAuthorityCutoverJobSettings
+      dev.caskeleton.bootstrap.autoconfigure.outbox.MessagingAuthorityCutoverApplicationRunner
       OutboxEventJpaRepository.deletePublishedBefore
       OutboxEventJpaRepository.countGroupedByStatus
       OutboxEventJpaRepository.findOldestUnpublishedOccurredAtByEventType