【后端接口】节日烟花：道具燃放与全服庆祝

---烟花筒的使用：燃放与庆祝增益
function Firework.lit(actor)
    local player = class(actor)
    if not player then return false end
    if not checkitemw(actor, "烟花筒", 1) then
        sendmsg(actor, 1, "需要 1 支烟花筒")
        return false
    end
    takeitem(actor, "烟花筒", 1, 0, "燃放烟花")
    -- 周围 10 格玩家获得 30 分钟的庆祝增益
    for _, watcher in pairs(View.of(actor)) do
        addbuff(watcher, 23001, 1800, 1, actor, { [1] = 30 })
        playsound(watcher, 2050)
    end
    sendmsg(nil, 1, actor .. " 在" ..
        Map.nameOf(actor.mapId) .. "燃放了节日烟花！")
    return true
end

---节日期间的掉落加成：与烟花联动
setontimerex(108, 60)
function Firework.festival()
    local count = Firework.litToday()
    -- 全服燃放满 100 支触发 2 倍掉落 1 小时
    if count >= 100 and not Firework.boostOn then
        Firework.boostOn = true
        setsysvar("FestivalDrop", 2)
        sendmsg(nil, 1, "全服燃放满 100 支，掉落翻倍 1 小时！")
        Firework.expireAt = os.time() + 3600
    end
end