Bound Iberian pit-lake causal arrows to their actual study sites #1506

Record: kb/communities/Iberian_Pit_Lake_Stratified_Community.yaml.

The three downstream arrows encode co-occurring redox guilds, carbon consumption rather than its proposed cause, and an unsupported Thermoplasmatales-to-methanogen route. The five nodes combine NSC/Concepcion, Cueva de la Mora, FC/La Zarza and a deep borehole. These are not one assayed eight-member community. Several exact metabolite concentrations and interaction labels overstate the cited graph evidence.

Primary evidence: 2013 pit lakes, 2020 FC/La Zarza, 2022 Cueva de la Mora. Complete cached 2013/2020 main texts and embedded tables/captions read; 2022 reviewed at abstract scope because full-body access failed. No original images or external supplements inspected.

Repair every existing node and arrow, retain positive observations and predictions with site-specific scope, remove unsupported directions and precise graph quantities, and add an anchored knowledge gap. Do not erase geochemical attenuation or misstate omics predictions as no evidence. Test exact participants and uncertainty. No new causal structure is implied.

Dedup: 813 all-state issue bodies and ignored/hidden local artifacts searched. Prior #258 was a dangling-target defect in a different record; #1092/#1094 concern cache tooling. This is a scientific inference repair. Keep open until protected-main merge.