Named Substrate/Polkadot sr25519 verification conventions.

Substrate does not use bare schnorrkel's defaults — it pins the signing context to the ASCII bytes "substrate", and some message-signing flows wrap the payload in <Bytes>…</Bytes>. Each convention here is a named function backed by real-tooling vectors; adding a convention means adding a named function plus its vectors, never a hidden branch inside an ambiguous "verify".

All inputs are raw-byte binaries: the bare 64-byte signature (strip any MultiSignature 0x01 tag first) and the raw 32-byte public key. The return contract is identical to Sr25519.verify_raw/4.

Which function do I want?

• verify_raw_message/3 — the signer signed the message bytes directly under the "substrate" context, with no wrapping. This is what substrate-interface/subkey produce for sign(bytes), and what Bittensor hotkeys / the Epistula protocol use (Epistula signs the plain payload string "#{body}.#{uuid}.#{timestamp}.#{signed_for}" with no wrapping — construct that exact string on the caller side and pass it here).

• verify_wrapped_bytes/3 — the signer used the polkadot-js extension / signRaw message-signing convention (u8aWrapBytes), which wraps the message in <Bytes>…</Bytes> unless it is already wrapped or carries the Ethereum signed-message prefix — this function mirrors that conditional behavior exactly, so pass the message precisely as the dapp passed it to signRaw.

If a caller already holds the exact signed bytes (wrapped or otherwise), use Sr25519.verify_raw/4 with the "substrate" context directly.