🐛 Fixes

• Fix highlight clipping: remove redundant shoulder_softening (sigmoid H-D curve provides natural shoulder).
• Unified output model: density linear mapping + tone gamma=2.47 for both Fast and Accurate modes.
• Norm target raised 0.18→0.32 to compensate scatter/WB losses in Accurate pipeline.

🔧 Improvements

• Physically correct d_min per channel for C-41 color negative films (orange mask residual).
  • Kodak: R=0.14, G=0.16, B=0.19. Fuji: R=0.13, G=0.15, B=0.17.
  • Shadow color cast now emerges naturally from physics.