[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/scripts/changeTracker.ts

@@ -1,8 +1,8 @@
-import { LGraphCanvas, LiteGraph } from '@comfyorg/litegraph'
 import * as jsondiffpatch from 'jsondiffpatch'
 import _ from 'lodash'
 import log from 'loglevel'
 
+import { LGraphCanvas, LiteGraph } from '@/lib/litegraph/src/litegraph'
 import type { ExecutedWsMessage } from '@/schemas/apiSchema'
 import type { ComfyWorkflowJSON } from '@/schemas/comfyWorkflowSchema'
 import { useExecutionStore } from '@/stores/executionStore'