pub const NOISE_PATTERN_XX: &str = "Noise_XX_25519_AESGCM_SHA256\x00\x00\x00\x00";Expand description
Noise XX pattern name, zero-padded to HASHLEN (32 bytes) per Noise § 5.2.
Used on the first connect / pairing where the client has no cached server
static key. Mirrors WA Web’s M constant in WAWebOpenChatSocket.