Constant ALLOWED_JWT_ALGORITHMS 

const ALLOWED_JWT_ALGORITHMS: &[Algorithm];

Algorithms we accept for JWT signature verification.

Restricted to RSA-family algorithms because the only DecodingKey we build is from RSA components (n, e). Pinning the algorithm to a server-side allow-list also prevents the classic alg-confusion attack: a token with alg: "none" (no signature) or alg: "HS256" forged using the RSA public key as the HMAC secret cannot select a verification algorithm outside this set.