test: App Mode - widget reordering (#10685)

## Summary

Adds tests that simulate the user sorting the inputs and ensures they
are persisted and visible in app mode

## Changes

- **What**: 
- rework input/output selection helpers to accept widget/node names
- extract additional shared helpers

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-10685-test-App-Mode-widget-reordering-3316d73d3650813b8348da5f29fd01f8)
by [Unito](https://www.unito.io)

browser_tests/helpers/builderTestUtils.ts

@@ -1,11 +1,18 @@
 import { expect } from '@playwright/test'
 
 import type { ComfyPage } from '../fixtures/ComfyPage'
+import type { AppModeHelper } from '../fixtures/helpers/AppModeHelper'
 import type { NodeReference } from '../fixtures/utils/litegraphUtils'
 
+import { comfyExpect } from '../fixtures/ComfyPage'
 import { fitToViewInstant } from './fitToView'
 import { getPromotedWidgetNames } from './promotedWidgets'
 
+interface BuilderSetupResult {
+  inputNodeTitle: string
+  widgetNames: string[]
+}
+
 /**
  * Enter builder on the default workflow and select I/O.
  *
@@ -13,41 +20,48 @@ import { getPromotedWidgetNames } from './promotedWidgets'
  * to subgraph), then enters builder mode and selects inputs + outputs.
  *
  * @param comfyPage - The page fixture.
- * @param getInputNode - Returns the node to click for input selection.
- *   Receives the KSampler node ref and can transform the graph before
- *   returning the target node. Defaults to using KSampler directly.
- * @returns The node used for input selection.
+ * @param prepareGraph - Optional callback to transform the graph before
+ *   entering builder. Receives the KSampler node ref and returns the
+ *   input node title and widget names to select.
+ *   Defaults to KSampler with its first widget.
+ *   Mutually exclusive with widgetNames.
+ * @param widgetNames - Widget names to select from the KSampler node.
+ *   Only used when prepareGraph is not provided.
+ *   Mutually exclusive with prepareGraph.
  */
 export async function setupBuilder(
   comfyPage: ComfyPage,
-  getInputNode?: (ksampler: NodeReference) => Promise<NodeReference>
-): Promise<NodeReference> {
+  prepareGraph?: (ksampler: NodeReference) => Promise<BuilderSetupResult>,
+  widgetNames?: string[]
+): Promise<void> {
   const { appMode } = comfyPage
   await comfyPage.workflow.loadWorkflow('default')
 
   const ksampler = await comfyPage.nodeOps.getNodeRefById('3')
-  const inputNode = getInputNode ? await getInputNode(ksampler) : ksampler
+
+  const { inputNodeTitle, widgetNames: inputWidgets } = prepareGraph
+    ? await prepareGraph(ksampler)
+    : { inputNodeTitle: 'KSampler', widgetNames: widgetNames ?? ['seed'] }
 
   await fitToViewInstant(comfyPage)
   await appMode.enterBuilder()
   await appMode.steps.goToInputs()
-  await appMode.select.selectInputWidget(inputNode)
+
+  for (const name of inputWidgets) {
+    await appMode.select.selectInputWidget(inputNodeTitle, name)
+  }
 
   await appMode.steps.goToOutputs()
-  await appMode.select.selectOutputNode()
-
-  return inputNode
+  await appMode.select.selectOutputNode('Save Image')
 }
 
 /**
  * Convert the KSampler to a subgraph, then enter builder with I/O selected.
- *
- * Returns the subgraph node reference for further interaction.
  */
 export async function setupSubgraphBuilder(
   comfyPage: ComfyPage
-): Promise<NodeReference> {
-  return setupBuilder(comfyPage, async (ksampler) => {
+): Promise<void> {
+  await setupBuilder(comfyPage, async (ksampler) => {
     await ksampler.click('title')
     const subgraphNode = await ksampler.convertToSubgraph()
     await comfyPage.nextFrame()
@@ -58,10 +72,52 @@ export async function setupSubgraphBuilder(
     )
     expect(promotedNames).toContain('seed')
 
-    return subgraphNode
+    return {
+      inputNodeTitle: 'New Subgraph',
+      widgetNames: ['seed']
+    }
   })
 }
 
+/**
+ * Open the save-as dialog, fill name + view type, click save,
+ * and wait for the success dialog.
+ */
+export async function builderSaveAs(
+  appMode: AppModeHelper,
+  workflowName: string,
+  viewType: 'App' | 'Node graph' = 'App'
+) {
+  await appMode.footer.saveAsButton.click()
+  await comfyExpect(appMode.saveAs.nameInput).toBeVisible({ timeout: 5000 })
+  await appMode.saveAs.fillAndSave(workflowName, viewType)
+  await comfyExpect(appMode.saveAs.successMessage).toBeVisible({
+    timeout: 5000
+  })
+}
+
+/**
+ * Load a different workflow, then reopen the named one from the sidebar.
+ * Caller must ensure the page is in graph mode (not builder or app mode)
+ * before calling.
+ */
+export async function openWorkflowFromSidebar(
+  comfyPage: ComfyPage,
+  name: string
+) {
+  await comfyPage.workflow.loadWorkflow('default')
+  await comfyPage.nextFrame()
+  const { workflowsTab } = comfyPage.menu
+  await workflowsTab.open()
+  await workflowsTab.getPersistedItem(name).dblclick()
+  await comfyPage.nextFrame()
+
+  await comfyExpect(async () => {
+    const path = await comfyPage.workflow.getActiveWorkflowPath()
+    expect(path).toContain(name)
+  }).toPass({ timeout: 5000 })
+}
+
 /** Save the workflow, reopen it, and enter app mode. */
 export async function saveAndReopenInAppMode(
   comfyPage: ComfyPage,