🔆 Polarimetry: Stokes Vector, Analyzer Scan, Malus Law and Wave Plates (2D)

Polarimetry bench in 2D: linear light passes an optical rotator and a retarder, then a rotating analyzer. See the polarization ellipse, the Stokes vector and a least-squares fit of the noisy intensity scan. Same Stokes/Mueller kernel as the 3D page, with Malus, lossless-optics, fit and wave-plate checks.