B20 Control Audit

🆕 b20-safety tells you WHICH powers a B20 has; this tells you WHO holds them. Reads the token's role-based access control (mint / burn / seize-via-burnBlocked / pause / admin) from onchain role events and reports the exact controllers, how centralized they are, and whether admin has been renounced. The issuer-control map an agent needs before holding a regulated Base-native asset.