[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/schemas/apiSchema.ts

@@ -1,7 +1,7 @@
-import { LinkMarkerShape } from '@comfyorg/litegraph'
 import { z } from 'zod'
 import { fromZodError } from 'zod-validation-error'
 
+import { LinkMarkerShape } from '@/lib/litegraph/src/litegraph'
 import { colorPalettesSchema } from '@/schemas/colorPaletteSchema'
 import { zComfyWorkflow, zNodeId } from '@/schemas/comfyWorkflowSchema'
 import { zKeybinding } from '@/schemas/keyBindingSchema'

src/schemas/colorPaletteSchema.ts

@@ -1,6 +1,7 @@
-import { LiteGraph } from '@comfyorg/litegraph'
 import { z } from 'zod'
 
+import { LiteGraph } from '@/lib/litegraph/src/litegraph'
+
 const nodeSlotSchema = z.object({
   CLIP: z.string(),
   CLIP_VISION: z.string(),