✨ Features

• Film: Add FilmStyle system for systematic rendering style modifiers (Accurate, Artistic, Vintage, HighContrast, Pastel).
• Presets: Add artistic variants for popular films (Portra 400, Tri-X 400, Velvia 50, HP5 Plus 400).
• UI: Add FilmStyle selector to both Simple and Professional modes with horizontal button layout.
• UI: Trigger automatic reprocessing when switching between Simple and Professional modes.

🐛 Fixes

• Presets: Fix grain alpha values using correct formula (RMS/1000)² for all 51 films (was incorrectly RMS/1000).
• Presets: Restore original curve parameters for Portra 400, Tri-X 400, HP5 Plus, and Velvia 50.
• Grain: Add visual grain boost factor (25x) to compensate for display/perception differences - grain was physically correct but visually too weak.
• UI: Load preset values on image load to fix initial grain intensity issue (first load showed extreme grain).

💄 Style

• UI: Move Rendering Style to separate section with consistent grouping.
• UI: Change FilmStyle selector from dropdown to horizontal buttons for better UX.
• UI: Force white balance Off in Simple mode during processing.

♻️ Refactor

• Film: Add helper methods to FilmStyle enum (all(), name(), description(), short_description()) for cleaner UI code.

🙈 Chore

• Git: Add .DS_Store to .gitignore.

📄 Documentation

• README: Update snapshot image.