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/package.json

@@ -5,7 +5,7 @@
   "scripts": {
     "dev": "vite",
     "build": "vite build",
-    "typecheck": "tsc --noEmit",
+    "typecheck": "vue-tsc --noEmit",
     "test": "vitest run"
   },
   "dependencies": {
@@ -17,13 +17,16 @@
     "@lezer/common": "^1.5.3",
     "@lezer/highlight": "^1.2.5",
     "@lezer/markdown": "^1.8.0",
-    "shiki": "^4.5.0"
+    "shiki": "^4.5.0",
+    "vue": "^3.5.44"
   },
   "devDependencies": {
+    "@vitejs/plugin-vue": "^6.0.10",
     "commonmark-spec": "^0.31.2",
     "happy-dom": "^21.0.3",
-    "typescript": "^7.0.2",
+    "typescript": "^6.0.3",
     "vite": "^8.3.4",
-    "vitest": "^5.0.5"
+    "vitest": "^5.0.5",
+    "vue-tsc": "^3.3.13"
   }
 }