地图迷雾：未探索区域遮罩显示

-- 错误：全图无遮罩直开，探索感归零
function openWorldMap()
    showAllCells()
end

local seen = {}
local function reveal(cx, cy)
    seen[cx .. "_" .. cy] = true
    refreshFog()
end
local function refreshFog()
    for _, cell in ipairs(fogCells) do
        local vis = seen[cell.cx .. "_" .. cell.cy]
        cell.node:setOpacity(vis and 0 or 160)
    end
end