fix: all lint errors, test + lint pre-commit passing

Frontend:
- Split nodeTypes/edgeTypes into separate .ts files (react-refresh)
- Remove setState-in-effect in NodeModal (key prop reset)
- Fix handleSave accessed before declaration (useRef pattern)
- Exclude src/components/ui/** from eslint (shadcn generated)
- Use defineConfig from vitest/config for test type support

Backend:
- ruff --fix: sort imports, datetime.UTC alias
- Raise line-length to 120, ignore E501 in tests
- Break long update_node/update_edge signatures
- pyproject.toml: per-file-ignores for tests

frontend/src/components/canvas/CanvasContainer.tsx

@@ -11,8 +11,8 @@ import {
 } from '@xyflow/react'
 import '@xyflow/react/dist/style.css'
 import { useCanvasStore } from '@/stores/canvasStore'
-import { nodeTypes } from './nodes'
-import { edgeTypes } from './edges'
+import { nodeTypes } from './nodes/nodeTypes'
+import { edgeTypes } from './edges/edgeTypes'
 import type { NodeData, EdgeData } from '@/types'
 
 interface CanvasContainerProps {