feat: add ComfyUI integration for image generation

- Implemented ComfyUI API for generating images with various modes (text-to-image, image-to-image, inpaint, outpaint).
- Created GenerateSheet and associated controls for user input on generation settings.
- Added subtle scrollbar styles for improved UI experience.
- Enhanced canvas input handling to ignore key events when focused on editable elements.
- Optimized canvas resizing logic to prevent unnecessary dispatches.
- Introduced error handling for generation failures and loading models.
- Added functionality to upload images and masks for inpainting.

view/ToolOverlay.tsx

@@ -1,4 +1,4 @@
-import { Cursor, Eraser, Hand, PaintBrush, DropHalf, MagicWand } from "@phosphor-icons/react";
+import { Cursor, Eraser, Hand, PaintBrush, DropHalf, MagicWand, Sparkle } from "@phosphor-icons/react";
 import { commandIds } from "@commands/ids";
 import type { AppStore } from "@editor/store";
 import type { InteractionMode, ToolId } from "@editor/tools";
@@ -41,6 +41,8 @@ export function ToolOverlay({ activeTool, interactionMode, dispatch }: ToolOverl
 
 function iconForTool(tool: ToolId) {
   switch (tool) {
+    case "generate":
+      return Sparkle;
     case "brush":
       return PaintBrush;
     case "eraser":