feat: Enhance Bevel & Emboss effect with contour support and algorithm improvements

- Implemented contour lookup functionality for Bevel & Emboss effect to allow for custom contour curves.
- Added contour parameter to LayerStyle and updated related structures and functions.
- Improved emboss algorithm by fixing height field calculations and ensuring proper handling of outside pixels.
- Introduced tilt component for 3D emboss effect, enhancing visual depth.
- Optimized MAE grid search parameters for better performance and accuracy.
- Expanded Iced GUI panel for Bevel & Emboss to include contour selection and additional styling options.
- Updated example scripts to reflect changes in the API and new features.

hcie-io/examples/tune_mae_emboss.rs

@@ -203,7 +203,7 @@ fn search(
                 let (hl_buf, sh_buf) = hcie_fx::tuned::generate_bevel_tuned(
                     alpha, w, h, depth, size, soften, angle, altitude,
                     direction, technique, style,
-                    *blur, *hl_scale, *sh_scale, 1.0,
+                    *blur, *hl_scale, *sh_scale, 1.0, 0.05,
                 );
 
                 let mut out = src_pixels.to_vec();