Lua配置合并：默认表与覆盖表

-- 错误：直接用覆盖表，缺键全成 nil
local cfg = passedOptions
use(cfg.size, cfg.color)

local function merge(dft, over)
    local out = {}
    for k, v in pairs(dft) do
        out[k] = v
    end
    for k, v in pairs(over) do
        out[k] = v
    end
    return out
end
local dft = {size = 20, color = "white"}
local cfg = merge(dft, {color = "red"})
local label = panel:getChildByName("cfgText")
label:setString(cfg.size .. "/" .. cfg.color)