[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/utils/executableGroupNodeChildDTO.ts

@@ -1,3 +1,4 @@
+import type { GroupNodeHandler } from '@/extensions/core/groupNode'
 import {
   type ExecutableLGraphNode,
   ExecutableNodeDTO,
@@ -5,9 +6,7 @@ import {
   type LGraphNode,
   type NodeId,
   type SubgraphNode
-} from '@comfyorg/litegraph'
-
-import type { GroupNodeHandler } from '@/extensions/core/groupNode'
+} from '@/lib/litegraph/src/litegraph'
 
 export class ExecutableGroupNodeChildDTO extends ExecutableNodeDTO {
   groupNodeHandler?: GroupNodeHandler