CVE-2026-86039: libp2p: PeerStore accepts attacker-signed PeerRecords for a victim peer ID and stores certified attacker addresses

@libp2p/peer-store accepts a signed PeerRecord whose envelope is signed by one peer but whose payload claims a different peer ID. The vulnerable consumePeerRecord path verifies the envelope signature, but does not verify that the envelope signer is the same peer as the wrapped PeerRecord.peerId. As a result, an attacker can sign a record with their own key while placing a victim peer ID in the payload, causing attacker-controlled multiaddrs to be stored as certified addresses for the victim.