[refactor] Improve workflow domain organization (#5584)

* [refactor] move workflow domain to its own folder

* [refactor] Fix workflow platform architecture organization

- Move workflow rendering functionality to renderer/thumbnail domain
- Rename ui folder to management for better semantic clarity
- Update all import paths to reflect proper domain boundaries
- Fix test imports to use new structure

Architecture improvements:
- rendering → renderer/thumbnail (belongs with other rendering logic)
- ui → management (better name for state management and UI integration)

This ensures proper separation of concerns and domain boundaries.

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

Co-Authored-By: Claude <noreply@anthropic.com>

* [fix] Resolve circular dependency between nodeDefStore and subgraphStore

* [fix] Update browser test imports to use new workflow platform paths

---------

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

src/services/litegraphService.ts

@@ -24,8 +24,9 @@ import type {
   ISerialisableNodeOutput,
   ISerialisedNode
 } from '@/lib/litegraph/src/types/serialisation'
+import { useWorkflowStore } from '@/platform/workflow/management/stores/workflowStore'
+import type { NodeId } from '@/platform/workflow/validation/schemas/workflowSchema'
 import { useCanvasStore } from '@/renderer/core/canvas/canvasStore'
-import type { NodeId } from '@/schemas/comfyWorkflowSchema'
 import { transformInputSpecV2ToV1 } from '@/schemas/nodeDef/migration'
 import type {
   ComfyNodeDef as ComfyNodeDefV2,
@@ -44,7 +45,6 @@ import { useSettingStore } from '@/stores/settingStore'
 import { useSubgraphStore } from '@/stores/subgraphStore'
 import { useToastStore } from '@/stores/toastStore'
 import { useWidgetStore } from '@/stores/widgetStore'
-import { useWorkflowStore } from '@/stores/workflowStore'
 import { normalizeI18nKey } from '@/utils/formatUtil'
 import {
   isImageNode,