MARS-69 friction digest: id-bearing routes never clear minimum-volume floor

Digest groups on (message, route); route is logged as raw window.location.pathname, so any route carrying a práctica/entity uuid (e.g. /mi-cursada/[id]/editar) makes every occurrence its own group of one, permanently invisible to the digest regardless of sessionOnce dedup. Found by coder-mars-cc while fixing MARS-625 (practica-edit:time-warning, review:locked-by-student), but applies to every friction surface on an id-bearing route, not just those two. Fix: normalize route to its pattern (e.g. /mi-cursada/[id]/editar) at log time, not the raw pathname — also removes uuids from the digest per the commons no-raw-IDs-in-exports rule.