feat(icons): generate application icons in multiple sizes

This update introduces a new script to generate application icons in various sizes, including 32x32, 64x64, 128x128, and 512x512 pixels. The generated icons are now included in the Tauri configuration, ensuring that the application has the appropriate icons for different contexts.

- Added a script for generating icons from a source image
- Updated Tauri configuration to reference new icon sizes
- Included multiple icon formats for better compatibility

.claude/settings.local.json

@@ -92,7 +92,11 @@
       "Bash(rustfmt --check --edition 2021 src/git.rs)",
       "Bash(awk *)",
       "Bash(rustfmt --edition 2021 /tmp/blame_chunk.rs)",
-      "Read(//tmp/**)"
+      "Read(//tmp/**)",
+      "Bash(identify src-tauri/icons/GitCat.ico)",
+      "Bash(python3 -c \"import PIL; print\\(PIL.__version__\\)\")",
+      "Bash(python3 *)",
+      "Bash(xxd -l 16 src-tauri/icons/GitCat.ico)"
     ]
   }
 }