[contracts/shared] Define future on-chain verifier adapter boundary

[FlowmemoryAI]

Objective

Define the boundary for future on-chain verifier adapters that may consume FlowMemory receipt, report, or attestation hashes without deploying production verifier infrastructure yet.

Allowed folders

• contracts/shared/
• crypto/
• docs/DECISIONS/
• docs/SECURITY_MODEL.md

Forbidden folders

• contracts/RootfieldRegistry.sol unless separately approved
• deployment scripts
• tokenomics
• production L1/appchain implementation
• dynamic fee hooks
• zk proof implementation
• dashboard UI
• hardware CAD

Acceptance criteria

• Spec identifies which v0 hashes are safe as on-chain inputs: observationId, receiptHash, reportId, artifact root, and verifier signature digest.
• Spec states what on-chain adapters must not assume, including data availability, trustless verification, and contract-known txHash/logIndex.
• Prerequisites are listed before any Solidity adapter is implemented.
• Decision record links adapter work to accepted observation identity and verifier report schemas.

Risk level

High

Recommended agent

Protocol Contracts Agent with Crypto Agent review.

[FlowmemoryAI]

Closing as duplicate of #28. The crypto production-readiness pass added a local draft boundary doc at contracts/shared/RECEIPT_VERIFIER_BOUNDARY.md for #28 instead of tracking a second adapter-boundary issue.