feat: add POSTGRES_PORT support for PgBouncer connections and disable ssl mode

[felixschmetz]

Summary by cubic

Added POSTGRES_PORT and POSTGRES_SSLMODE to support PgBouncer connections with custom ports and to optionally disable SSL for internal traffic. This improves connection flexibility while keeping compatibility with providers that require SSL (e.g., Azure PostgreSQL).

• New Features
  • Support POSTGRES_PORT in the async SQLAlchemy URI (default 5432).
  • Add POSTGRES_SSLMODE (default "prefer"); when set to "disable", pass ssl=False to asyncpg.
  • Usage: set POSTGRES_PORT to your PgBouncer port and POSTGRES_SSLMODE=disable for cluster-internal PgBouncer.

^{Written for commit e130995. Summary will update automatically on new commits.}