# Architect — F-002 Database foundation with module-owned schemas

done -> work/artifacts/F-002/architect.md

## Decision summary
- Migration tool: node-pg-migrate + pg driver. Pure npm deps, boring, up/down support, version table owned by the tool.
- Single PostgreSQL instance, module ownership by table prefix (`<module>_<table>`). No per-module PG schemas — simplicity first; prefix rule documented and exemplified.
- Baseline migration only ships foundation objects (extensions + `app_meta`). Business tables arrive with their modules.
- Dev environment: docker-compose with postgres:16-alpine + redis:7-alpine, one command up.
- Env via Node 22 `--env-file`; fail fast when `DATABASE_URL` missing. Integration tests skip explicitly when `TEST_DATABASE_URL` absent — no silent magic.

## Expected blast radius

```text
EXPECTED BLAST RADIUS

Modules modified: src/infrastructure/db (new)
Modules indirectly affected: none (no HTTP API, no business modules)
Database changes: baseline migration (extensions, app_meta) - greenfield
API changes: none
Events added/changed: none
Risk level: low
```

## Handoff to implementer
Follow specs/F-002-database-foundation/TASKS.md. Docker daemon is available (verified at intake). Definition of done for build stage: compose up green, migrations up/down/up demonstrated against real PostgreSQL, integration tests passing with TEST_DATABASE_URL, and evidence in implementer.md.