【引擎触发】canpush：推动技能的施法前校验

---canpush: 推动技能施法前触发
function canpush(self, targetActor)
    local player = class(self)
    if not player then return false end
    local target = getplayerbyname(targetActor)
    if not target then return false end
    -- 等级压制：等级低于目标 5 级推不动
    if self:GetLevel() < target:GetLevel() - 5 then
        sendmsg(self, 1, "对方稳如泰山，推动失败")
        return false
    end
    -- 沙巴克皇宫内禁止推动（占领判定不受干扰）
    if target.mapId == "shabake_palace" then
        sendmsg(self, 1, "皇宫内禁止推动")
        return false
    end
    return true
end

---落点：推到的格子必须合法
function Push.landing(actor, targetActor, dist)
    local target = getplayerbyname(targetActor)
    if not target then return false end
    -- 沿推动方向逐格检查
    for step = dist, 1, -1 do
        local lx = target.x + Push.dx * step
        local ly = target.y + Push.dy * step
        if gridattr(target.mapId, lx, ly, 1) then
            mapmove(target, target.mapId, lx, ly, 0)
            sendmsg(target, 1, "被推开了！")
            return true
        end
    end
    sendmsg(self, 1, "目标身后无落脚之地")
    return false
end