Function msg_fs_sync_full 

pub fn msg_fs_sync_full(
    nonce: u16,
    flags: u16,
    latency_ms: u16,
    inline_max: u32,
    path: &str,
    exclude: &str,
    src_pty_id: Option<u16>,
) -> Vec<u8> 

Every C2S_FS_SYNC variant, in field order. The optional trailers are self-describing through their flags — EXCLUDE first, FROM_PTY last — which is what lets a parser skip one to reach the other.