Convex-hull / rate-quality plotter (asset B3)

A small, dependency-free (pure standard-library) Python tool that turns a grid of measured (resolution, bitrate, quality) points into the convex hull — the optimal bitrate-resolution frontier behind a per-title ladder. It computes the upper non-dominated frontier across resolutions, marks the crossover bitrates where the winning resolution changes, writes a rate-quality plot with the hull overlaid as a dependency-free SVG (no matplotlib), and computes the BD-rate (Bjontegaard delta-rate, the bit