【引擎触发】魔法盾：法师减伤盾的消耗与破碎机制

-- 技能释放触发：魔法盾
function QF.MagicShield(plr)
    if plr:HasState(STATE_SHIELD) then return false end
    if plr:GetMP() < 50 then return false, "魔法不足" end
    local lv = plr:GetSkillLevel("魔法盾")
    plr:AddState(STATE_SHIELD, {
        expireAt = os.time() + 60000,
        reduce = 0.3 + lv * 0.1,
        mpPerSec = 5 + lv * 2,
    })
    return true
end

-- 受伤结算触发：魔法盾减免
function QF.OnDamage(plr, damage, dmgType)
    local shield = plr:GetState(STATE_SHIELD)
    if not shield then return damage end
    local reduced = math.floor(damage * (1 - shield.reduce))
    plr:CostMP(shield.mpPerSec + math.floor(damage * 0.05))
    if plr:GetMP() <= 0 then
        plr:ClearState(STATE_SHIELD)
        plr:SendMsg("魔法盾破碎！")
    end
    return reduced
end