Event-driven projector creates/collapses NEEDS_REPLY items from message.sent
(traceId propagated; inbox.item.created emitted) and resolves them to DONE on
message.read; idempotent via processed-event ledger. markRead now emits a
message.read outbox event (atomic). OutboxRelay runs on a 500ms timer in the
app (off in tests). Shared resetDb (TRUNCATE CASCADE) fixes cross-spec FK
isolation. 32 tests green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Reuses support-service bootstrap/health/prisma patterns. Kernel-only Prisma
schema (scope/source_handle/actor/channel/thread/participant/interaction/
message_part/outbox/processed_event) with orgId/appId NOT NULL and
@@unique([scopeId, idempotencyKey]). Health verified: {status:ok,db:true}.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>