We'll keep the door open for side-by-side support of Postgres in
the background, but due to SQLite's type system quirks we cannot
use the same DDL for both databases, so we would have to maintain
two sets of DDL (schema init and schema migration scripts) at once.
Interested future contributors can shoulder this maintenance burden
if they so choose.
Everything is a scalar value now, and while this does involve more
boilerplate it will also catch type conversion issues like
"1" + 0 === "10" in the future.
