[refactor] Move thumbnail functionality to renderer/core domain (#5586)

Move thumbnail functionality from src/renderer/thumbnail/ to src/renderer/core/thumbnail/
to align with domain-driven design architecture. Thumbnail generation is core rendering
infrastructure and belongs alongside other core renderer utilities.

Changes:
- Move useWorkflowThumbnail.ts and graphThumbnailRenderer.ts to renderer/core/thumbnail/
- Update all import paths in consuming files
- Fix relative imports within moved files

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: Claude <noreply@anthropic.com>

src/components/topbar/WorkflowTab.vue

@@ -43,7 +43,7 @@ import {
 import { useWorkflowService } from '@/platform/workflow/core/services/workflowService'
 import { ComfyWorkflow } from '@/platform/workflow/management/stores/workflowStore'
 import { useWorkflowStore } from '@/platform/workflow/management/stores/workflowStore'
-import { useWorkflowThumbnail } from '@/renderer/thumbnail/useWorkflowThumbnail'
+import { useWorkflowThumbnail } from '@/renderer/core/thumbnail/useWorkflowThumbnail'
 import { useSettingStore } from '@/stores/settingStore'
 import { useWorkspaceStore } from '@/stores/workspaceStore'
 

src/platform/workflow/core/services/workflowService.ts

@@ -8,7 +8,7 @@ import {
   useWorkflowStore
 } from '@/platform/workflow/management/stores/workflowStore'
 import { ComfyWorkflowJSON } from '@/platform/workflow/validation/schemas/workflowSchema'
-import { useWorkflowThumbnail } from '@/renderer/thumbnail/useWorkflowThumbnail'
+import { useWorkflowThumbnail } from '@/renderer/core/thumbnail/useWorkflowThumbnail'
 import { app } from '@/scripts/app'
 import { blankGraph, defaultGraph } from '@/scripts/defaultGraph'
 import { downloadBlob } from '@/scripts/utils'

src/platform/workflow/management/stores/workflowStore.ts

@@ -6,7 +6,7 @@ import { t } from '@/i18n'
 import type { LGraph, Subgraph } from '@/lib/litegraph/src/litegraph'
 import { ComfyWorkflowJSON } from '@/platform/workflow/validation/schemas/workflowSchema'
 import type { NodeId } from '@/platform/workflow/validation/schemas/workflowSchema'
-import { useWorkflowThumbnail } from '@/renderer/thumbnail/useWorkflowThumbnail'
+import { useWorkflowThumbnail } from '@/renderer/core/thumbnail/useWorkflowThumbnail'
 import { api } from '@/scripts/api'
 import { app as comfyApp } from '@/scripts/app'
 import { ChangeTracker } from '@/scripts/changeTracker'

src/renderer/core/thumbnail/graphThumbnailRenderer.ts

@@ -6,7 +6,7 @@ import {
   calculateNodeBounds
 } from '@/renderer/core/spatial/boundsCalculator'
 
-import { renderMinimapToCanvas } from '../extensions/minimap/minimapCanvasRenderer'
+import { renderMinimapToCanvas } from '../../extensions/minimap/minimapCanvasRenderer'
 
 /**
  * Create a thumbnail of the current canvas's active graph.

src/renderer/core/thumbnail/useWorkflowThumbnail.ts

@@ -1,7 +1,8 @@
 import { ref } from 'vue'
 
 import { ComfyWorkflow } from '@/platform/workflow/management/stores/workflowStore'
-import { createGraphThumbnail } from '@/renderer/thumbnail/graphThumbnailRenderer'
+
+import { createGraphThumbnail } from './graphThumbnailRenderer'
 
 // Store thumbnails for each workflow
 const workflowThumbnails = ref<Map<string, string>>(new Map())

tests-ui/tests/renderer/thumbnail/composables/useWorkflowThumbnail.spec.ts

@@ -6,7 +6,7 @@ import {
   useWorkflowStore
 } from '@/platform/workflow/management/stores/workflowStore'
 
-vi.mock('@/renderer/thumbnail/graphThumbnailRenderer', () => ({
+vi.mock('@/renderer/core/thumbnail/graphThumbnailRenderer', () => ({
   createGraphThumbnail: vi.fn()
 }))
 
@@ -22,10 +22,10 @@ vi.mock('@/scripts/api', () => ({
 }))
 
 const { useWorkflowThumbnail } = await import(
-  '@/renderer/thumbnail/useWorkflowThumbnail'
+  '@/renderer/core/thumbnail/useWorkflowThumbnail'
 )
 const { createGraphThumbnail } = await import(
-  '@/renderer/thumbnail/graphThumbnailRenderer'
+  '@/renderer/core/thumbnail/graphThumbnailRenderer'
 )
 const { api } = await import('@/scripts/api')