[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/services/subgraphService.ts

@@ -2,8 +2,7 @@ import {
   type ExportedSubgraph,
   type ExportedSubgraphInstance,
   type Subgraph
-} from '@comfyorg/litegraph'
-
+} from '@/lib/litegraph/src/litegraph'
 import type { ComfyWorkflowJSON } from '@/schemas/comfyWorkflowSchema'
 import type { ComfyNodeDef as ComfyNodeDefV1 } from '@/schemas/nodeDefSchema'
 import { app as comfyApp } from '@/scripts/app'