feat: implement inpainting functionality with mask handling

- Added `createMaskedPixelReplacementSource` function to handle pixel replacement using inpainting.
- Introduced `buildInpaintBundle` to prepare inpainting data including mask generation and validation.
- Created utility functions for mask operations such as `applyMaskedContentModeToRgba`, `expandRectWithinBounds`, and others for mask manipulation.
- Developed tests for inpainting preparation and mask raster utilities to ensure functionality and correctness.
- Implemented mask raster operations including inversion, feathering, blurring, and more.

app/app.ts

@@ -1,4 +1,5 @@
 import { documentCommands } from "@commands/document";
+import { generationCommands } from "@commands/generation";
 import { historyCommands } from "@commands/history";
 import { commandIds } from "@commands/ids";
 import { createCommandRegistry } from "@commands/registry";
@@ -12,7 +13,7 @@ import { createAppStore } from "@editor/store";
 export type ImageStudioApp = ReturnType<typeof createImageStudioApp>;
 
 export function createImageStudioApp(options?: { documentName?: string; createDefaultArtboard?: boolean }) {
-  const registry = createCommandRegistry([...viewportCommands, ...selectionCommands, ...documentCommands, ...toolCommands, ...transformCommands, ...historyCommands]);
+  const registry = createCommandRegistry([...viewportCommands, ...selectionCommands, ...documentCommands, ...toolCommands, ...generationCommands, ...transformCommands, ...historyCommands]);
   const store = createAppStore(createInitialAppState(options?.documentName), registry);
 
   if (options?.createDefaultArtboard !== false) {