【策划架构】Lua服务降级：祖玛教主榜首榜的本地兜底

local function showRank(actor)
    local list = fetchRemote()      -- 远程一挂，对话直接报错
    sendmsg(actor, 1, "榜首 " .. list[1].name)
end

local FALLBACK = {{name = "裁决之杖守卫", score = 52000}}
local CACHE = {}
local function showRank(actor)
    local ok, list = pcall(fetchRemote)
    if not ok or not list then list = CACHE end   -- 二级缓存
    if not list then list = FALLBACK end          -- 三级兜底
    CACHE = list
    sendmsg(actor, 1, "祖玛教主榜首 " .. list[1].name)
end