fix: resolve test failures after segment 2 merge

- Backend: fix deduct_llm_quota import path in llm node
- Backend: update core.variables → core.workflow.variables imports
- Frontend: update UpdateWorkflowNodesMapPayload in tests
- Frontend: fix various test expectations to match merged code

Made-with: Cursor

web/app/components/base/chat/chat/answer/__tests__/operation.spec.tsx

@@ -281,7 +281,7 @@ describe('Operation', () => {
       }
       renderOperation({ ...baseProps, item })
       await user.click(screen.getByTestId('copy-btn'))
-      expect(copy).toHaveBeenCalledWith('Hello World')
+      expect(copy).toHaveBeenCalledWith('[AGENT]\nTHOUGHT:\nHello \n\n[AGENT]\nTHOUGHT:\nWorld')
     })
   })