pub const DEFAULT_DATABASE_URL: &str = "postgres://localhost/ig";Expand description
Credential-less placeholder used for DATABASE_URL when it is not configured.
Persistence is optional, so an unset DATABASE_URL is not fatal at config
construction; this placeholder lets Config::new produce a value while
deliberately carrying NO username or password. It is not a working
connection string — any component that actually needs Postgres must fail
when it tries to connect. Never hard-code real credentials here.