SPO Tools v1.1

SPO Tools v1.1. Adds the CIP-136 rationale-witness step: the online client canonicalises a hand-authored vote rationale (URDNA2015, per CIP-100) and the air-gapped signer produces the CIP-100 author witness with the pool cold key, so a vote's on-chain anchor renders as a proper rationale instead of raw JSON. The signer only ever signs a canonical governance-metadata body, never a transaction. Assets: online and signer, each as glibc (x86-64), static musl (x86-64), and arm64 (Raspberry Pi). Verify downloads against SHA256SUMS.txt.