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/src/app/Workspace.vue

@@ -0,0 +1,59 @@
+<script setup lang="ts">
+import { computed, onBeforeUnmount, onMounted } from 'vue'
+import { api } from './api'
+import EditorPane from './EditorPane.vue'
+import Icon from './Icon.vue'
+import NoteBanner from './NoteBanner.vue'
+import { noteTitle } from './paths'
+import Sidebar from './Sidebar.vue'
+import TabBar from './TabBar.vue'
+import { activeTab, flushAll, startWorkspace, stopWorkspace, toast, ws } from './workspace'
+
+const emit = defineEmits<{ logout: [] }>()
+const title = computed(() => (ws.active ? noteTitle(ws.active) : 'RawMark'))
+const saving = computed(() => activeTab()?.dirty)
+
+async function logout() {
+  await flushAll()
+  try {
+    await api.logout()
+  } catch {
+    toast('退出失败')
+    return
+  }
+  stopWorkspace()
+  emit('logout')
+}
+
+// 移动端：从屏幕左边缘右滑打开侧栏
+let touchX: number | null = null
+function onTouchStart(e: TouchEvent) {
+  touchX = e.touches[0].clientX < 24 ? e.touches[0].clientX : null
+}
+function onTouchMove(e: TouchEvent) {
+  if (touchX !== null && e.touches[0].clientX - touchX > 60) {
+    ws.sidebarOpen = true
+    touchX = null
+  }
+}
+
+onMounted(() => void startWorkspace())
+onBeforeUnmount(stopWorkspace)
+</script>
+
+<template>
+  <div class="rm-shell" :class="{ 'sidebar-open': ws.sidebarOpen }" @touchstart.passive="onTouchStart" @touchmove.passive="onTouchMove">
+    <aside class="rm-sidebar"><Sidebar @logout="logout" /></aside>
+    <div class="rm-backdrop" @click="ws.sidebarOpen = false" />
+    <main class="rm-main">
+      <header class="rm-mobile-bar">
+        <button class="rm-icon-btn" title="目录" @click="ws.sidebarOpen = true"><Icon name="menu" :size="20" /></button>
+        <span class="rm-mobile-title">{{ title }}</span>
+        <span class="rm-save-state" :class="{ on: saving }" />
+      </header>
+      <TabBar />
+      <NoteBanner />
+      <EditorPane />
+    </main>
+  </div>
+</template>