The runtime role (lovebug) doesn't have CREATE on the petalbrain database
even though it owns the second_brain schema, so a bare
`CREATE SCHEMA IF NOT EXISTS` errors out with permission denied. Gate
the bootstrap on a pg_namespace lookup so we only attempt the create
when the schema is genuinely missing — operators bootstrap it once as
postgres superuser, alembic just respects it afterward.
The smoke test exercises the full Postgres + embedding path against a
live DB + Ollama (autoskipped otherwise): writes an extraction, embeds
the summary, asserts public.embeddings has the expected row count, and
re-embeds to verify the delete-before-insert idempotency.
