[BUG]: I cannot have reliable way of positioning title and legend on top without overlapping each other

Description

As plotly is responsive there's currently no way to place both legend and title on the top of the chart so that title and legend do not overlap (seems legend doesn't take into account title/subtitle). I know I have some tools which can help (like setting top margin/playing with y/maxheight/yref) but all of them aren't reliable as resizing the window (thus resizing the chart)/having long trace names/etc breaks all hardcoded configurations.

Steps to reproduce

Here's the demo: https://python-fiddle.com/examples/plotly?checkpoint=1757947390
Code behind it:

import plotly.express as px

df = px.data.gapminder().query("year==2007")
fig = px.scatter(df, x="gdpPercap", y="lifeExp", color="continent",
    size="pop", size_max=45, log_x=True)

fig.update_layout(legend=dict(
    orientation="h",
    entrywidth=70,
    yanchor="bottom",
    y=1.02,
    xanchor="center",
    x=1
))

fig.update_layout(title="Very long loong long long long title")

fig.show()

Notes

I'm posting python code here intentionally as I think this is the basic issue of the plotly.js rather than lack of configuration/bugs in Python wrapper.

从链接的 Python-Fiddle 复现开始，跟踪 plotly.js 在长标题和水平图例下的 responsive 布局行为。通过调整图表大小并改变 trace-name 的长度来确认结果；完成的标准是标题和图例在没有硬编码间距的情况下保持不重叠，并且有一项回归检查覆盖该复现。