docs(m181): probe derivation buckets every rubric row — executable or declared exclusion

Greptile round 3 on the pre-swap invariant: prose-evidence rows, joined
commands, and prerequisite phrases would either fail generation or skip
silently under a bare count assert. Every row now lands as a normalized
executable probe or an Indy-signed exclusion; the assert counts both.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>