Shor's Algorithm: Phasor-Sum Interference Map

This is the 2D companion to the 3D Shor's-algorithm period-finding visualizer, computed independently rather than flattened from the 3D scene. It renders the quantum Fourier transform's output not as bar heights but as the literal Argand-diagram arithmetic that produces them: for each candidate output index k, the surviving values left in the collapsed register each contribute one unit phasor step, and the diagram chains those steps head-to-tail so you can watch constructive alignment (a straight walk that closes far from the origin) and destructive cancellation (a curl that closes near the origin) happen as geometry, not just as a height. A synchronized spectrum strip beneath the diagram — a genuinely 2D-native view — plots the full, correctly-normalised probability P(k) across every output index, with auto-scan continuously sweeping k so the two views stay in lock-step. Measuring samples a real outcome from that distribution and runs the same continued-fraction period recovery (and classical gcd factoring step) as the 3D version.