fix: guard progress_text before canvas init (#11174)

## Summary
Prevent early `progress_text` websocket events from throwing before the
graph canvas is initialized.

## Changes
- **What**: Guard `handleProgressText()` until `canvasStore.canvas`
exists, and add a regression test for a startup-time `progress_text`
event arriving before `GraphCanvas` finishes initialization.

## Review Focus
Confirm this is the right guard point for the startup race between
`GraphView` websocket binding and `GraphCanvas` async setup, and that
progress text behavior is unchanged once the canvas is ready.

## Validation
- `pnpm exec eslint src/stores/executionStore.ts
src/stores/executionStore.test.ts`
- `pnpm exec vitest run src/stores/executionStore.test.ts -t "should
ignore progress_text before the canvas is initialized"`
- `pnpm test:unit -- --run src/stores/executionStore.test.ts` still
reports one unrelated isolated-file failure in
`nodeLocatorIdToExecutionId` on current `main`

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-11174-fix-guard-progress_text-before-canvas-init-3406d73d3650813dad23d511fb51add5)
by [Unito](https://www.unito.io)

src/stores/executionStore.test.ts

@@ -7,12 +7,21 @@ import { useMissingNodesErrorStore } from '@/platform/nodeReplacement/missingNod
 import { executionIdToNodeLocatorId } from '@/utils/graphTraversalUtil'
 
 // Create mock functions that will be shared
-const mockNodeExecutionIdToNodeLocatorId = vi.fn()
-const mockNodeIdToNodeLocatorId = vi.fn()
-const mockNodeLocatorIdToNodeExecutionId = vi.fn()
+const {
+  mockNodeExecutionIdToNodeLocatorId,
+  mockNodeIdToNodeLocatorId,
+  mockNodeLocatorIdToNodeExecutionId,
+  mockShowTextPreview
+} = vi.hoisted(() => ({
+  mockNodeExecutionIdToNodeLocatorId: vi.fn(),
+  mockNodeIdToNodeLocatorId: vi.fn(),
+  mockNodeLocatorIdToNodeExecutionId: vi.fn(),
+  mockShowTextPreview: vi.fn()
+}))
 
 import type * as WorkflowStoreModule from '@/platform/workflow/management/stores/workflowStore'
 import type { NodeProgressState } from '@/schemas/apiSchema'
+import type { LGraphCanvas } from '@/lib/litegraph/src/LGraphCanvas'
 import { createMockLGraphNode } from '@/utils/__tests__/litegraphTestUtils'
 import { createTestingPinia } from '@pinia/testing'
 
@@ -38,7 +47,7 @@ declare global {
 
 vi.mock('@/composables/node/useNodeProgressText', () => ({
   useNodeProgressText: () => ({
-    showTextPreview: vi.fn()
+    showTextPreview: mockShowTextPreview
   })
 }))
 
@@ -431,6 +440,56 @@ describe('useExecutionStore - reconcileInitializingJobs', () => {
   })
 })
 
+describe('useExecutionStore - progress_text startup guard', () => {
+  let store: ReturnType<typeof useExecutionStore>
+
+  function fireProgressText(detail: {
+    nodeId: string
+    text: string
+    prompt_id?: string
+  }) {
+    const handler = apiEventHandlers.get('progress_text')
+    if (!handler) throw new Error('progress_text handler not bound')
+    handler(new CustomEvent('progress_text', { detail }))
+  }
+
+  beforeEach(() => {
+    vi.clearAllMocks()
+    apiEventHandlers.clear()
+    setActivePinia(createTestingPinia({ stubActions: false }))
+    store = useExecutionStore()
+    store.bindExecutionEvents()
+  })
+
+  it('should ignore progress_text before the canvas is initialized', async () => {
+    const { useCanvasStore } =
+      await import('@/renderer/core/canvas/canvasStore')
+    useCanvasStore().canvas = null
+
+    expect(() =>
+      fireProgressText({
+        nodeId: '1',
+        text: 'warming up'
+      })
+    ).not.toThrow()
+
+    expect(mockShowTextPreview).not.toHaveBeenCalled()
+  })
+
+  it('should call showTextPreview when canvas is available', async () => {
+    const mockNode = createMockLGraphNode({ id: 1 })
+    const { useCanvasStore } =
+      await import('@/renderer/core/canvas/canvasStore')
+    useCanvasStore().canvas = {
+      graph: { getNodeById: vi.fn(() => mockNode) }
+    } as unknown as LGraphCanvas
+
+    fireProgressText({ nodeId: '1', text: 'warming up' })
+
+    expect(mockShowTextPreview).toHaveBeenCalledWith(mockNode, 'warming up')
+  })
+})
+
 describe('useExecutionErrorStore - Node Error Lookups', () => {
   let store: ReturnType<typeof useExecutionErrorStore>
 

src/stores/executionStore.ts

@@ -527,7 +527,7 @@ export const useExecutionStore = defineStore('execution', () => {
     // Handle execution node IDs for subgraphs
     const currentId = getNodeIdIfExecuting(nodeId)
     if (!currentId) return
-    const node = canvasStore.getCanvas().graph?.getNodeById(currentId)
+    const node = canvasStore.canvas?.graph?.getNodeById(currentId)
     if (!node) return
 
     useNodeProgressText().showTextPreview(node, text)