[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/executableGroupNodeDto.ts

@@ -4,7 +4,7 @@ import {
   type ISlotType,
   LGraphEventMode,
   type LGraphNode
-} from '@comfyorg/litegraph'
+} from '@/lib/litegraph/src/litegraph'
 
 export const GROUP = Symbol()