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/AuthView.vue

@@ -0,0 +1,64 @@
+<script setup lang="ts">
+import { computed, ref } from 'vue'
+import { api, ApiError } from './api'
+
+const props = defineProps<{ mode: 'setup' | 'login' }>()
+const emit = defineEmits<{ done: [] }>()
+
+const code = ref('')
+const password = ref('')
+const confirm = ref('')
+const error = ref('')
+const busy = ref(false)
+const isSetup = computed(() => props.mode === 'setup')
+
+async function submit() {
+  error.value = ''
+  if (isSetup.value && password.value !== confirm.value) {
+    error.value = '两次输入的密码不一致'
+    return
+  }
+  busy.value = true
+  try {
+    if (isSetup.value) await api.setup(code.value, password.value)
+    else await api.login(password.value)
+    emit('done')
+  } catch (err) {
+    error.value = err instanceof ApiError ? err.message : '网络错误，请检查连接'
+  } finally {
+    busy.value = false
+  }
+}
+</script>
+
+<template>
+  <div class="rm-auth">
+    <form class="rm-auth-card" @submit.prevent="submit">
+      <h1>RawMark</h1>
+      <p v-if="isSetup" class="rm-auth-hint">
+        首次使用，请设置登录密码。启动码位于服务器数据目录的 <code>setup-code.txt</code> 中。
+      </p>
+      <label v-if="isSetup">
+        <span>启动码</span>
+        <input v-model="code" autocomplete="one-time-code" autocapitalize="characters" placeholder="XXXX-XXXX" required />
+      </label>
+      <label>
+        <span>密码</span>
+        <input
+          v-model="password"
+          type="password"
+          :autocomplete="isSetup ? 'new-password' : 'current-password'"
+          :minlength="isSetup ? 8 : undefined"
+          required
+          autofocus
+        />
+      </label>
+      <label v-if="isSetup">
+        <span>确认密码</span>
+        <input v-model="confirm" type="password" autocomplete="new-password" required />
+      </label>
+      <p v-if="error" class="rm-auth-error">{{ error }}</p>
+      <button class="rm-btn rm-btn-primary" type="submit" :disabled="busy">{{ isSetup ? '完成设置' : '登录' }}</button>
+    </form>
+  </div>
+</template>