src/idp/well-known-did-nostr.js serves DID documents with "type": "Multikey" + publicKeyMultibase, but the @context is ["https://w3id.org/did", "https://w3id.org/nostr/context"] — neither entry defines Multikey, and https://w3id.org/did returns text/html (not a JSON-LD context). So the served documents do not fully JSON-LD-expand.

Multikey / publicKeyMultibase are defined in Controlled Identifiers v1.0 (https://www.w3.org/ns/cid/v1). Notably jss already uses that context in src/keys/provision.js:141, so this is also an internal inconsistency.

Fix: change the served DID-doc @context to ["https://www.w3.org/ns/cid/v1", "https://w3id.org/nostr/context"].

Mirrors the spec change in nostrcg/did-nostr#91 (issue nostrcg/did-nostr#90). Safe: a grep finds no code asserting the literal @context value; auth/resolution match on the verification method / pubkey, not the context.