[refactor] Migrate litegraph imports from npm package to local subtree

- Updated all imports from '@comfyorg/litegraph' to '@/lib/litegraph/src/'
- Replaced deep dist imports with direct source paths
- Updated CSS import in main.ts
- All imports now use the @ alias consistently

src/extensions/core/groupNodeManage.ts

@@ -2,8 +2,7 @@ import {
   type LGraphNode,
   type LGraphNodeConstructor,
   LiteGraph
-} from '@comfyorg/litegraph'
-
+} from '@/lib/litegraph/src/litegraph'
 import { useToastStore } from '@/stores/toastStore'
 
 import { type ComfyApp, app } from '../../scripts/app'