feat: add tools for common operations

[ojasinha]

What's this PR doing?

• Adds new tools for various common operations in Libresprite:
  • create_sprite
  • create_layer
  • fill_layer
  • draw_circle
  • draw_rectangle
  • draw_line
  • draw_ellipse
  • put_pixel
  • flood_fill
  • get_sprite_info
  • delete_layer
  • replace_color
• Expands documentation and examples to demonstrate usage of these new tools and combined workflows. The prompt now advises using run_script only for advanced custom cases.

[ojasinha]

Just a heads up though, a lot of the times the non-painting tools — create_sprite, create_layer — don't actually work as intended even though they are being called with the correct arguments. For example, if I ask the model to create a 64x64 pixel sprite it does correctly call the create_sprite tool with the correct arguments for width and height. But once the sprite is actually created the dimensions are always 32x32 pixel. Although sometimes it does work for some reason. 🤷‍♂️

[sksarvesh007]

LGTM!