Smoke Tests: 004-postgres-database-replacement

• Primary smoke script: scripts/test-state-004-postgres-database-replacement.sh

Required checks for this state:

• Compose services are running with PostgreSQL healthy.
• Baseline PostgreSQL schema and seed data are loaded.
• Ingress health/UI routes are functional.
• Core baseline service smoke checks still pass.
• Realtime account stream behavior still passes through trade-feed path.