Go module on indigo; env-var config with logged dev defaults; typed sentinel errors (incl. ErrTombstoned for the materializer's missing-vs-deleted branch); goose migrations for ap_objects (with origin discriminator + ap_published_at), bridged_actors (frozen terminal consent, sticky handle/key), communities, inbox_events; postgres stores behind per-domain interfaces with real-DB tests. Reviewed by 4 Claude specialty agents + Codex gpt-5.5 + Gemini 3.1 Pro + GLM 5.2; 18 consolidated findings applied (critical: UpsertActor could NULL escrowed signing keys; important: identity-drift rejection, atomic SoftDelete, tombstone/missing distinction, origin column, CI-proof test skips, constraint-name error mapping). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>