Lua路径规范化：分隔与回退的处理

-- 错误：原样串做缓存键，同资源多键
cache[path] = res

local function normPath(p)
    p = p:gsub("[\\/]+", "/")
    local parts = {}
    for seg in p:gmatch("[^/]+") do
        if seg == ".." and #parts > 0 then
            table.remove(parts)
        elseif seg ~= "." then
            parts[#parts + 1] = seg
        end
    end
    return table.concat(parts, "/")
end
local label = panel:getChildByName("pathText")
label:setString(normPath("ui\\main//icon/./logo.png"))