Function embedding_fingerprints_match 

pub fn embedding_fingerprints_match(host: &str, provider: &str) -> bool

Whether a host may send its embeddings to a provider: exact string equality of the two fingerprints (SPEC.md §E1).

Equality is required rather than, say, matching only the model id, because dimension and normalization both change what a vector means. A host that sent a 384-dimension unnormalized vector to a provider indexed on 384 L2-normalized vectors would get plausible-looking, meaningless scores — precisely the class of silent wrongness the protocol exists to make loud.