【后端接口】装备升品：品质跃迁与保底碎片的引擎实现

---升品结算：品质跃迁与碎片消耗
function upgradeQuality(actor, slot)
    local item = actor.bag[slot]
    local q = item:GetQuality()
    if q >= 5 then return false, "已达最高品质" end
    if not actor:TakeItemByName("升品碎片", UPGRADE_COST[q]) then
        return false, "升品碎片不足"
    end
    if math.random(1, 100) <= SUCCESS_RATE[q] then
        item:SetQuality(q + 1)
        recalcabilitys(actor)
        sendmsg(actor, 1, "升品成功！装备品质提升")
        QF_Broadcast(actor:GetName() .. " 将装备升至 " .. (q + 1) .. " 品")
    else
        actor:AddItemByName("保底碎片", UPGRADE_COST[q], 1)
        sendmsg(actor, 1, "升品失败，返还保底碎片")
    end
    return true
end

---四品以上的升品全服播报
function upgradeBroadcast(actor, newQuality)
    if newQuality >= 4 then
        QF_Broadcast(actor:GetName() .. " 将装备升至 " .. newQuality .. " 品！")
    end
end