【运维发布】日志切割：按天滚动与压缩归档

---全局定时器 42 号：每分钟检查切换时刻
setontimerex(42, 60)
function LogRotate.tick()
    local today = os.date("%Y%m%d")
    if LogRotate.day ~= today then
        LogRotate.day = today
        LogRotate.switch(today)
    end
end

function LogRotate.switch(today)
    LogRotate.flush()
    local yday = os.date("%Y%m%d", os.time() - 86400)
    local old = "server_" .. yday .. ".log"
    LogRotate.compress(old)
end

---压缩昨天的日志并清理超期文件
function LogRotate.compress(fname)
    os.rename(fname, fname .. ".tmp")
    Zip.pack(fname .. ".gz", fname .. ".tmp")
    os.remove(fname .. ".tmp")

    -- 保留 14 天，超期即删
    local cutoff = os.time() - 14 * 86400
    for f in LogRotate.listdir() do
        local d = f:match("server_(%d+)%.log%.gz")
        if d and os.time({ year = d:sub(1,4), month = d:sub(5,6),
            day = d:sub(7,8), hour = 12 }) < cutoff then
            os.remove(f)
        end
    end
end