Returns a common_sql.Driver backed by PostgreSQL via the pog library.

Call driver() once at application startup and pass it down. Each call creates one Erlang atom for the pool name — do not call it in a loop.

Closing a pog connection pool has no explicit stop API; the pool runs as an OTP actor for the lifetime of the application. common_sql.close/2 is a no-op for this driver. Use pog.supervised/1 to manage the pool in an OTP supervision tree.