Adopt the eager non-voter pipeline
Under eager, non-voters pre-fetch the EB body and missing closure during the diffusion window in parallel with voter activity (rather than starting from scratch when the certRB arrives, which is the lazy alternative we previously documented). Add a new "Where does p_cert come from?" sub-paragraph in ยง3.1 between the bug-fix pseudocode and the existing "Why P_cert, not P(EB exists)" subsection.