【入门夯实】触发重复：同一帧触发的幂等习惯

local function onSignup(actor)
    actor = getplayerbyname(actor)
    takeitem(actor, "祖玛头像", 1, 0, "攻城报名")
    setplayvar(actor, "HUMAN", "SiegeJoined", 1, 1)
    sendmsg(actor, 1, "报名成功！")
end

local function onSignup(actor)
    actor = getplayerbyname(actor)
    local now = os.clock() * 1000
    local last = tonumber(getplayvar(actor, "HUMAN", "SignupTick")) or 0
    if now - last < 200 then
        return
    end
    setplayvar(actor, "HUMAN", "SignupTick", math.floor(now), 0)
    if not takeitem(actor, "祖玛头像", 1, 0, "攻城报名") then
        sendmsg(actor, 1, "背包中没有祖玛头像。")
        return
    end
    setplayvar(actor, "HUMAN", "SiegeJoined", 1, 1)
    sendmsg(actor, 1, "报名成功！")
end

local function alreadyJoined(actor)
    return getplayvar(actor, "HUMAN", "SiegeJoined") == 1
end

local function guard(name, key, windowMs)
    local now = os.clock() * 1000
    local last = tonumber(getplayvar(name, "HUMAN", key)) or 0
    if now - last < windowMs then
        return false
    end
    setplayvar(name, "HUMAN", key, math.floor(now), 0)
    return true
end