Repair Pelotomaculum syntrophy evidence and substrate-specific claims #1686

CommunityMech:000052, PMID12361280. Preserve observed coculture growth and hydrogen-transfer directions; replace temperature-as-metabolism evidence. Fumarate reduction and pure-culture fermentation contradict universal obligate partner dependence. Do not assign acetate and CO2 as universal products of every alcohol/diol. Restore evidence attribution for substrate-dependent coaggregation to PMID16332758, separating microscopy and diffusion modeling. No new nodes/arrows. Close only after protected-main merge.

Searched 962 all-state issue titles/bodies and read six matches (#1397, #1394, #1272, #1232, #1217, #1216); local hidden/ignored-inclusive search found 62 files, excluding .git/docs/site/references_cache. Additional exact coaggregation-reference search found no matching issue. Comments not exhaustively searched. Four whole records; primary PES main text/correction, pepper-growth main text and pepper-biocontrol PDF reviewed; syntrophy species paper and coaggregation evidence abstract/caption limited. Self-adversarial review, not independent approval.