feat(recipes): opt-in workflow embedding for widget recipe saves

Add a "Save Recipe with Workflow" action next to "Save Recipe" in the LoRA
widget context menu. It posts the current UI-format graph alongside the save
request so the stored preview embeds it and the recipe can send the graph back
to ComfyUI. Embedding stays opt-in rather than folded into "Save Recipe": the
workflow is by far the largest metadata field and its widget values may carry
sensitive data.

- web/comfyui: new menu entry; saveRecipeDirectly({ embedWorkflow }) posts the
  UI graph and reports the outcome (embedded / skipped) via toasts.
- save_recipe_from_widget handler: reads an optional JSON workflow field so the
  long-standing body-less POST keeps working, including from cached clients.
- RecipePersistenceService.save_recipe_from_widget: embeds the graph through
  the existing optimize_image workflow path, derives has_workflow by detection,
  and skips graphs above MAX_WORKFLOW_EMBED_BYTES with workflow_skipped.

tests/frontend/utils/saveRecipeDirectly.test.js

@@ -0,0 +1,92 @@
+import { describe, it, beforeEach, afterEach, expect, vi } from 'vitest';
+
+const { UTILS_MODULE, APP_MODULE, API_MODULE, BASE_PATH_MODULE } = vi.hoisted(() => ({
+  UTILS_MODULE: new URL('../../../web/comfyui/loras_widget_utils.js', import.meta.url).pathname,
+  APP_MODULE: new URL('../../../scripts/app.js', import.meta.url).pathname,
+  API_MODULE: new URL('../../../scripts/api.js', import.meta.url).pathname,
+  BASE_PATH_MODULE: new URL('../../../web/comfyui/base_path.js', import.meta.url).pathname,
+}));
+
+const toastAdd = vi.fn();
+const graphToPrompt = vi.fn();
+
+vi.mock(APP_MODULE, () => ({
+  app: {
+    graphToPrompt,
+    extensionManager: { toast: { add: toastAdd } },
+  },
+}));
+
+vi.mock(API_MODULE, () => ({
+  api: { fetchApi: vi.fn() },
+}));
+
+vi.mock(BASE_PATH_MODULE, () => ({
+  lmUrl: (path) => `/lm${path}`,
+}));
+
+async function runSave(options, responseBody) {
+  let captured = null;
+  globalThis.fetch = vi.fn(async (url, init) => {
+    captured = { url, init };
+    return { json: async () => responseBody };
+  });
+
+  const { saveRecipeDirectly } = await import(UTILS_MODULE);
+  await saveRecipeDirectly(options);
+  return captured;
+}
+
+describe('saveRecipeDirectly', () => {
+  beforeEach(() => {
+    graphToPrompt.mockResolvedValue({
+      workflow: { nodes: [{ id: 1 }], last_node_id: 1 },
+      output: { 1: { class_type: 'KSampler' } },
+    });
+  });
+
+  afterEach(() => {
+    delete globalThis.fetch;
+    vi.clearAllMocks();
+  });
+
+  it('posts no workflow by default', async () => {
+    const captured = await runSave(undefined, { success: true, has_workflow: false });
+
+    expect(captured.init.body).toBe('{}');
+    expect(JSON.parse(captured.init.body)).not.toHaveProperty('workflow');
+  });
+
+  it('embeds the UI-format graph when asked', async () => {
+    const captured = await runSave(
+      { embedWorkflow: true },
+      { success: true, has_workflow: true }
+    );
+
+    const body = JSON.parse(captured.init.body);
+    expect(body.workflow).toEqual({ nodes: [{ id: 1 }], last_node_id: 1 });
+    expect(captured.init.headers['Content-Type']).toBe('application/json');
+  });
+
+  it('reports a skipped oversized workflow as a warning', async () => {
+    await runSave(
+      { embedWorkflow: true },
+      { success: true, has_workflow: false, workflow_skipped: 'too_large' }
+    );
+
+    const lastToast = toastAdd.mock.calls.at(-1)[0];
+    expect(lastToast.severity).toBe('warn');
+    expect(lastToast.summary).toBe('Recipe Saved without Workflow');
+    expect(lastToast.detail).toContain('too large');
+  });
+
+  it('reports a successful embed distinctly from a plain save', async () => {
+    await runSave(
+      { embedWorkflow: true },
+      { success: true, has_workflow: true }
+    );
+
+    const lastToast = toastAdd.mock.calls.at(-1)[0];
+    expect(lastToast.summary).toBe('Recipe Saved with Workflow');
+  });
+});