feat(ui): streamline workspace settings and remove sharing

Unify compact workspace controls and panel transitions, move directory actions into the context menu, and remove backlink UI.

Reorganize settings with searchable sections, per-setting resets, shortcut search, and accurate save feedback.

Remove sharing UI, APIs, authentication helpers, and storage code; provide a transactional cleanup script with retirement tests. Reject directories during orphan image cleanup and cover mixed-batch preservation.

web/src/app/TreeNode.vue

@@ -3,7 +3,6 @@ import { computed, nextTick, ref, watch } from 'vue'
 import Icon from './Icon.vue'
 import { basename, inAssetDir, isImage, joinPath } from './paths'
 import { contextSelection, expanded, selectedPaths, selectPath, type TreeNode } from './tree'
-import { minimalPaths } from './selection'
 import { batchFiles, exportFiles } from './batch'
 import { createFolder, createNote, move, openNote, renameTarget, ws } from './workspace'
 
@@ -80,7 +79,7 @@ function commitRename() {
   if (target && target !== props.node.path) void move(props.node.path, target)
 }
 
-function runMenu(action: 'note' | 'folder' | 'import' | 'images' | 'rename' | 'move' | 'share' | 'delete' | 'export') {
+function runMenu(action: 'note' | 'folder' | 'import' | 'images' | 'rename' | 'move' | 'delete' | 'export') {
   menuOpen.value = false
   const path = props.node.path
   if (action === 'note' || action === 'folder') {
@@ -89,7 +88,6 @@ function runMenu(action: 'note' | 'folder' | 'import' | 'images' | 'rename' | 'm
   } else if (action === 'import') ws.importing = path
   else if (action === 'images') { ws.imagesAll = false; ws.images = path }
   else if (action === 'rename') ws.renaming = path
-  else if (action === 'share') ws.sharing = minimalPaths(selectedPaths)
   else if (action === 'move') ws.moving = [...selectedPaths]
   else if (action === 'export') void exportFiles([...selectedPaths])
   else void batchFiles('delete', [...selectedPaths])
@@ -177,7 +175,7 @@ function onDrop(e: DragEvent) {
       />
       <Icon v-if="image" name="image" :size="18" />
       <span v-if="!isRenaming" class="rm-tree-name">{{ node.dir ? node.name : node.name.replace(/\.md$/, '') }}</span>
-      <button class="rm-icon-btn rm-tree-more" title="更多操作" @click.stop="menuOpen ? (menuOpen = false) : showMenu()">
+      <button v-if="!isRenaming" class="rm-icon-btn rm-tree-more" title="更多操作" @click.stop="menuOpen ? (menuOpen = false) : showMenu()">
         <Icon name="more" />
       </button>
     </div>
@@ -193,7 +191,6 @@ function onDrop(e: DragEvent) {
         <button v-if="image && selectedPaths.size === 1" @click="menuOpen = false; ws.image = node.path"><Icon name="image" />预览 / 替换图片</button>
         <button v-if="!assetDir && selectedPaths.size === 1" @click="runMenu('rename')"><Icon name="edit" />重命名</button>
         <button v-if="!assetDir" @click="runMenu('move')"><Icon name="folder" />移动到…</button>
-        <button @click="runMenu('share')"><Icon name="link" />分享</button>
         <button @click="runMenu('export')"><Icon name="note" />导出 Markdown</button>
         <button v-if="!assetDir" class="danger" @click="runMenu('delete')"><Icon name="trash" />删除</button>
       </div>