fix(doctor): L1: reporting_roles inspects the Tamanu role, not alertd's

[dannash100]

reporting_roles resolved its role with WHERE rolname = current_user, so it reported the privileges of the role alertd connects as (alertd), never Tamanu's. That role has no CREATEROLE and ADMIN on nothing, so the check fails on every 2.60+ server: has_createrole: false, roles_administrable: 0.

• bind the role from config.db.username instead
• skip when the config carries no db username, Broken when that role has no pg_roles row
• role added to the details, so the alert says which role it looked at

[passcod]

oh good catch, it used to go via Tamanu's role