[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/constants/coreSettings.ts

@@ -1,5 +1,4 @@
-import { LinkMarkerShape, LiteGraph } from '@comfyorg/litegraph'
-
+import { LinkMarkerShape, LiteGraph } from '@/lib/litegraph/src/litegraph'
 import type { ColorPalettes } from '@/schemas/colorPaletteSchema'
 import type { Keybinding } from '@/schemas/keyBindingSchema'
 import { NodeBadgeMode } from '@/types/nodeSource'