DID · VC 시연
`did:opus:<b64u(Ed25519 pubkey)>` self-certifying DID + W3C VC Ed25519Signature2020
1) DID 발급
POST /api/did/create
2) VC 발급
POST /api/did/vc/issue (server-side 데모 issuer 키)
3) VC 검증
POST /api/did/vc/verify · 변조 케이스 토글로 비교
`did:opus:<b64u(Ed25519 pubkey)>` self-certifying DID + W3C VC Ed25519Signature2020
POST /api/did/create
POST /api/did/vc/issue (server-side 데모 issuer 키)
POST /api/did/vc/verify · 변조 케이스 토글로 비교