Add so-postgres Salt states and integration wiring

Phase 1 of the PostgreSQL central data platform:
- Salt states: init, enabled, disabled, config, ssl, auth, sostatus
- TLS via SO CA-signed certs with postgresql.conf template
- Two-tier auth: postgres superuser + so_postgres application user
- Firewall restricts port 5432 to manager-only (HA-ready)
- Wired into top.sls, pillar/top.sls, allowed_states, firewall
  containers map, docker defaults, CA signing policies, and setup
  scripts for all manager-type roles

salt/postgres/map.jinja

@@ -0,0 +1,7 @@
+{# Copyright Security Onion Solutions LLC and/or licensed to Security Onion Solutions LLC under one
+   or more contributor license agreements. Licensed under the Elastic License 2.0 as shown at
+   https://securityonion.net/license; you may not use this file except in compliance with the
+   Elastic License 2.0. #}
+
+{% import_yaml 'postgres/defaults.yaml' as PGDEFAULTS %}
+{% set PGMERGED = salt['pillar.get']('postgres', PGDEFAULTS.postgres, merge=True) %}