Efficient frontier fit

The prompt

Build a chart game about the efficient frontier. I see a scatter of investments: risk along the bottom, expected return up the side. The good ones form an upper edge. I have to draw a smooth curve along that edge, only inside a marked range of risk, not across the whole chart.

I get a few tries. After each try, show me my curve on the cloud and tell me how far off I am. I can stop early and keep my best. A close curve should score well. A curve that misses the edge by a lot should score poorly. Do not draw the answer curve for me before I am done. I should still see the cloud, because that is what I am fitting.

Several different markets. The same market should show the same cloud every time.

# AI : shared Action contract — the page posts {"move": "..."}; keep this shape.
from pydantic import BaseModel


class Action(BaseModel):
    move: str