✨ Features

• Vignetting: cos⁴ lens falloff model in output space (~25% corner darkening).
• Micro motion blur: multi-frequency hand tremor simulation with Brownian trajectory.
  • UI: Motion Blur slider, seed control, trajectory + dwell weight visualization.
• Radial MTF: center-sharp, edge-soft blur (replaces uniform MTF).
• Chromatic aberration: R/B channel radial scaling for edge RGB fringing.
• Film stock analyzer: PSD shape, isotropy, signal dependency, film detection scoring.
  • Parallelized with rayon, xtask runs in release mode.

🐛 Fixes

• Self-calibrating exposure norm via binary search (consistent brightness across presets).