♻️ Refactor

• IO: Separate EXIF metadata building from file I/O operations.
• IO: Unify image encoding and EXIF writing to memory (Vec<u8>) before file output.
• IO: Use write_to_vec() instead of write_to_file() for EXIF metadata to enable cross-platform support.
• IO: Remove platform-specific #[cfg] guards from build_exif_metadata() - now works on both desktop and WASM.
• IO: Consolidate file I/O to single point: std::fs::write() for desktop, handle.write() for WASM.
• UI: Split controls.rs into modular components (film_list, technical, simple).
• UI: Split app.rs into modular components (io, state, update).
• GPU: Split gpu_pipelines.rs into modular pipeline stages.
• Presets: Split into manufacturer-specific modules (kodak, fujifilm, ilford, vintage).
• App: Extract EXIF orientation utils to shared module.

💄 Style

• UI: Update window size to 1200x800 and rename title.

🔧 Fixes

• Presets: Fix imports after module refactoring.
• Presets: Fix get_stocks() function calls in all preset modules.
• Examples: Update preset function names after module split.