Function parse_key_material 

pub fn parse_key_material(bytes: &[u8]) -> Result<ParsedKey, CryptoError>

Parse any supported PKCS8 DER (or raw seed) to extract seed + public key + curve.

This is the single source of truth for “what curve is this key?” The curve is detected here and carried in TypedSeed — never re-guessed.

Usage:

let parsed = parse_key_material(&pkcs8_bytes)?;
let sig = sign(&parsed.seed, message)?;