【工具链】行会活跃度看板：贡献数据的周报生成

---行会周数据的聚合任务
function GuildDashboard.generate(guildId)
    local week = os.date("%Y_W%W")
    local dash = {
        donate = GuildFund.weekSum(guildId, week),
        tasks = GuildTask.weekDone(guildId, week),
        boss = GuildBoss.weekAttend(guildId, week),
        chat = GuildChat.weekMsg(guildId, week),
    }
    dash.score = dash.donate * 0.3 + dash.tasks * 0.4 + dash.boss * 0.2 + math.min(dash.chat, 500) * 0.1
    QF_PersistJson("guild_dash_" .. guildId .. "_" .. week, dash)
    return dash
end

function GuildDashboard.decayAlert(guildId)
    local this = GuildDashboard.generate(guildId)
    local last = QF_LoadJson("guild_dash_" .. guildId .. "_prev") or { score = 0 }
    if last.score > 0 and this.score < last.score * 0.5 then
        QF_NotifyOps("行会活跃度腰斩", guildId .. " " .. last.score .. "->" .. this.score)
    end
end