fix(editor): recover missing files and synchronize section toggle

frontend/src/features/editor/EditorHeader.vue

@@ -10,6 +10,24 @@ const editorStore = useEditorStore()
 const workspaceStore = useWorkspaceStore()
 const { actionDialog, resolveAction, askConfirm } = useActionDialog()
 const reloadError = ref('')
+const needsRecovery = computed(() => ['conflict', 'external_changed'].includes(editorStore.saveStatus))
+const missingFile = computed(() => needsRecovery.value && editorStore.currentFilePath === workspaceStore.activeFilePath && !workspaceStore.activeFile && !workspaceStore.treeRefreshError)
+function downloadCopy() {
+  const url = URL.createObjectURL(new Blob([editorStore.content], { type: 'text/markdown;charset=utf-8' }))
+  const link = document.createElement('a')
+  link.href = url
+  link.download = `${(editorStore.currentFilePath?.split('/').pop() ?? 'note.md').replace(/\.md$/i, '')}-recovered.md`
+  document.body.append(link); link.click(); link.remove()
+  setTimeout(() => URL.revokeObjectURL(url), 1000)
+}
+async function discard() {
+  const path = editorStore.currentFilePath, snapshot = editorStore.content
+  if (!path || !(await askConfirm(t('关闭将丢弃当前编辑内容。需要保留时，请先下载 Markdown 副本。确认关闭？', 'Closing discards the current editor content. Download a Markdown copy first if needed. Close?')))) return
+  if (!(await editorStore.discardExternalChanges(path, snapshot))) return
+  workspaceStore.closeFile(path)
+  workspaceStore.setActiveFile(null)
+  reloadError.value = ''
+}
 async function reload() {
   const path = editorStore.currentFilePath, snapshot = editorStore.content
   if (!(await askConfirm(t('重新加载会丢弃当前未保存内容。请先复制需要保留的文字。继续吗？', 'Reload discards unsaved edits. Copy any text you need to keep first. Continue?')))) return
@@ -29,7 +47,10 @@ const statusText = computed<Record<string, string>>(() => ({
     <div class="file-identity"><strong>{{ workspaceStore.activeFile?.name ?? t('未命名笔记', 'Untitled note') }}</strong><small>{{ workspaceStore.activeFilePath }}</small></div>
     <div class="editor-actions">
       <span class="save-status" :class="editorStore.saveStatus">{{ statusText[editorStore.saveStatus] }}</span>
-      <button v-if="['conflict', 'external_changed'].includes(editorStore.saveStatus)" class="button-secondary" @click="reload">{{ t('重新加载外部版本', 'Reload external version') }}</button>
+      <button v-if="needsRecovery && !missingFile" class="button-secondary" @click="reload">{{ t('重新加载外部版本', 'Reload external version') }}</button>
+      <span v-if="missingFile" class="save-status conflict">{{ t('原文件已删除或移动', 'Original file deleted or moved') }}</span>
+      <button v-if="needsRecovery" class="button-secondary" @click="downloadCopy">{{ t('下载 Markdown 副本', 'Download Markdown copy') }}</button>
+      <button v-if="needsRecovery" class="button-secondary" @click="discard">{{ t('关闭当前笔记', 'Close current note') }}</button>
       <span v-if="reloadError" class="save-status conflict" role="alert">{{ reloadError }}</span>
       <div class="mode-switch" :aria-label="t('编辑模式', 'Editor mode')">
         <button type="button" :class="{ active: editorStore.mode === 'wysiwyg' }" @click="editorStore.setMode('wysiwyg')">{{ t('写作', 'Writing') }}</button>
@@ -53,6 +74,7 @@ const statusText = computed<Record<string, string>>(() => ({
 .file-identity { display: grid; min-width: 0; }
 .file-identity strong, .file-identity small { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
 .file-identity small { color: var(--color-text-tertiary); font-size: var(--font-size-xs); }
+.editor-actions { flex-wrap: wrap; justify-content: flex-end; }
 .editor-actions, .mode-switch { display: flex; align-items: center; gap: var(--space-sm); }
 .save-status { color: var(--color-text-tertiary); font-size: var(--font-size-xs); }
 .save-status.dirty, .save-status.external_changed { color: var(--color-warning); }