feat: add node translation editor for i18n management

- Add /nodes/[nodeId]/i18n page for editing node translations
- Implement translation interface with language selection and field editing
- Support for adding custom translation fields beyond default ones
- Include comprehensive error handling and success feedback
- Add Storybook stories with various scenarios and mock data
- Document feature implementation and usage in docs/

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: snomiao

src/stories/pages/NodeTranslationEditor.stories.tsx

@@ -2,7 +2,7 @@ import type { Meta, StoryObj } from '@storybook/nextjs-vite'
 import { http, HttpResponse } from 'msw'
 import { CAPI } from '@/src/mocks/handlers'
 import { NodeStatus, PublisherStatus } from '@/src/api/generated'
-import NodeTranslationEditor from '../../../pages/nodes/[nodeId]/translations'
+import NodeTranslationEditor from '../../../pages/nodes/[nodeId]/i18n'
 
 const meta: Meta<typeof NodeTranslationEditor> = {
     title: 'Pages/NodeTranslationEditor',