(database_url: string): Promise<CreateDbResult> Create a database connection based on a URL.
Returns the Db instance, a typed close callback, driver type, and display name.
The close callback is bound to the actual driver — callers never need to
know which driver is in use.
For direct driver construction without URL routing, import
create_pg_db from db_pg.ts or create_pglite_db from db_pglite.ts.
database_url
connection URL (postgres://, postgresql://, file://, or memory://)
stringreturns
Promise<CreateDbResult> database instance, close callback, type, and display name