【网络通信】消息回执：已读状态与送达确认的轻量同步

-- 消息回执：序列号同步
local player = class(actor)
local function syncReadPos(player, mailSeq, chatSeq)
    local lastMail = tonumber(getplayvar(player, "HUMAN", "ReadMailSeq") or 0)
    local lastChat = tonumber(getplayvar(player, "HUMAN", "ReadChatSeq") or 0)
    if mailSeq > lastMail then
        setplayvar(player, "HUMAN", "ReadMailSeq", mailSeq, true)
    end
    if chatSeq > lastChat then
        setplayvar(player, "HUMAN", "ReadChatSeq", chatSeq, true)
    end
    sendmsg(player, 1, 0, "已读位置同步：邮件 " .. mailSeq .. "，聊天 " .. chatSeq)
end

-- 未读计算：推算与合并上报
local player = class(actor)
local function unreadCount(player)
    local latest = tonumber(getsysvar("MailLatestSeq") or 0)
    local read = tonumber(getplayvar(player, "HUMAN", "ReadMailSeq") or 0)
    return math.max(0, latest - read)
end
local function onHeartbeatWithRead(player)
    local unread = unreadCount(player)
    if unread ~= tonumber(getplayvar(player, "HUMAN", "LastUnread") or -1) then
        setplayvar(player, "HUMAN", "LastUnread", unread, false)
        sendluamsg(player, 9999, unread, 0, 0, "mail")
    end
end