Dot-separated channel name (e.g. "public.news.tech"
or a <hex>.<segments> private channel).
identity is a full Reticulum Identity (holds both private keys, so it can
encrypt, decrypt, and derive its lxmf.delivery hash); channelHash is
the 16-byte channel identity hash used as the rfed routing label.
Derives a channel's deterministic Identity and 16-byte channel hash from its plain-text name.
The channel's private key bundle is
seed ‖ seed(the same 32-byteSHA-256(name)scalar used for both X25519 and Ed25519), matching the Rust reference'sprivate_key_bundle = seed || seedconvention.