【运维发布】错误聚合：相同堆栈的合并计数

---错误入桶：堆栈前三帧做指纹
function ErrAgg.capture(err, trace)
    local frames = {}
    for f in trace:gmatch("([%w_%.]+):%d+:") do
        frames[#frames + 1] = f
        if #frames >= 3 then break end
    end
    local fp = table.concat(frames, "|")
    local bucket = ErrAgg.buckets[fp]
    if not bucket then
        bucket = { count = 0, first = err, at = os.time(), sample = trace }
        ErrAgg.buckets[fp] = bucket
    end
    bucket.count = bucket.count + 1
    if bucket.count == 100 then
        ErrAgg.alert(fp, bucket)
    end
end

---全局定时器 48 号：每分钟输出 TopN
setontimerex(48, 60)
function ErrAgg.report()
    local list = {}
    for fp, b in pairs(ErrAgg.buckets) do
        list[#list + 1] = { fp = fp, count = b.count, at = b.at }
    end
    table.sort(list, function(a, b) return a.count > b.count end)
    for i = 1, math.min(10, #list) do
        Ops.log(("Top%d %s x%d"):format(i, list[i].fp, list[i].count))
    end
    ErrAgg.buckets = {}
end