Function log_first_use_pointer 

pub fn log_first_use_pointer()

Emits an info-level log pointing at the iso20022 docs URL, exactly once per process. Idempotent.

Resolves AC7.

Examples

use ssg::seo::jsonld::iso20022::log_first_use_pointer;
// Idempotent — second call is a no-op.
log_first_use_pointer();
log_first_use_pointer();