feat: add generation cancel job functionality and improve job handling

- Introduced `generationCancelJob` command ID in `commands/ids.ts`.
- Added `GenerationCancelJobPayload` type in `commands/payloads.ts`.
- Enhanced job status to include "cancelled" in `editor/state.ts`.
- Updated `runGenerationJob` to accept an `AbortSignal` and handle cancellation.
- Implemented cancellation logic in `runGenerate` and related functions.
- Added tests for job cancellation in `operations/generation/workflow.test.ts`.
- Improved layer rendering logic to prevent stack overflow in `editor/document-indexes.ts`.
- Added raster size assertions in `platform/browser/rasterLimits.ts` for image processing limits.
- Enhanced image file handling to check for size limits in `platform/browser/imageFiles.ts`.
- Updated UI components to reflect job cancellation state in `view/GenerationJobStatus.tsx` and `view/bottom-controls/GenerateActionControls.tsx`.

platform/comfy/generationClient.ts

@@ -4,8 +4,8 @@ export async function fetchGenerationOptions(): Promise<unknown> {
   return response.json() as Promise<unknown>;
 }
 
-export async function requestGeneration(body: unknown): Promise<{ source: string; mimeType: string }> {
-  const response = await fetch("/api/comfy/generate", { method: "POST", headers: { "content-type": "application/json" }, body: JSON.stringify(body) });
+export async function requestGeneration(body: unknown, signal?: AbortSignal): Promise<{ source: string; mimeType: string }> {
+  const response = await fetch("/api/comfy/generate", { method: "POST", headers: { "content-type": "application/json" }, body: JSON.stringify(body), signal });
   if (!response.ok) throw new Error(await response.text());
   return response.json() as Promise<{ source: string; mimeType: string }>;
 }