feat(web): add Vue workspace with file tree, tabs, autosave and live sync

- Login and first-run setup screens
- File tree with inline create/rename, context menu, drag-and-drop
  move and trash with undo; all operations update the UI first and roll
  back on failure
- Tabs keep a CodeMirror state each; edits autosave after 500 ms with
  If-Match revisions, unsent edits persist in IndexedDB, and conflicts
  or remote deletions surface as banners with explicit choices
- WebSocket events sync external edits, moves and deletions into open
  tabs; reconnects trigger a full resync
- Pasted or dropped images show instantly and upload to note.assets/
- Responsive layout with a swipe-in sidebar drawer on phones
- Switch to TypeScript 6: vue-tsc does not support TypeScript 7 yet

web/vite.config.ts

@@ -1,6 +1,18 @@
+import vue from '@vitejs/plugin-vue'
 import { defineConfig } from 'vitest/config'
 
 export default defineConfig({
+  plugins: [vue()],
+  build: {
+    rolldownOptions: {
+      // demo.html 为免登录的编辑器演示页，供自动化性能/交互测试使用
+      input: { index: 'index.html', demo: 'demo.html' },
+    },
+  },
   worker: { format: 'es' },
+  server: {
+    // 开发时把 API 与 WebSocket 转发给本地 Go 服务
+    proxy: { '/api': { target: 'http://127.0.0.1:8080', ws: true } },
+  },
   test: { environment: 'node' },
 })