newdrive/docs/adr/0002-opaque-object-identities.md

ADR-0002: Opaque object IDs and same-directory promotion

Status: Accepted

Managed objects use opaque physical IDs. PostgreSQL maps SHA-256 content identities to physical objects. Partials and completed blobs share one shard directory so final promotion is a same-directory rename. Blob-manifest export is required because the filesystem alone is not self-describing.