fix: 修复渲染进程5个bug（path未定义、editorWrapper未定义、死代码清理）

renderer/index.html

@@ -199,7 +199,7 @@
         </div>
         <div class="welcome-tips">
           <p>💡 提示：可以直接拖拽 .md 文件到窗口打开</p>
-          <p>⌨️ 快捷键：Ctrl+O 打开 | Ctrl+S 保存 | Ctrl+1/2/3 切换视图 | Ctrl+T 新建标签</p>
+          <p>⌨️ 快捷键：Ctrl+O 打开 | Ctrl+S 保存 | Ctrl+F 搜索 | Ctrl+H 替换 | Ctrl+1/2/3 视图 | Ctrl+T 标签</p>
         </div>
       </div>
     </div>

renderer/renderer.js

@@ -1180,8 +1180,9 @@
     const overlay = document.createElement('div');
     overlay.id = 'search-highlights';
     overlay.style.cssText = 'position:absolute;top:0;left:0;right:0;bottom:0;pointer-events:none;overflow:hidden;z-index:1;';
-    editorWrapper.style.position = 'relative';
-    editorWrapper.appendChild(overlay);
+    const wrapper = document.getElementById('editor-wrapper');
+    wrapper.style.position = 'relative';
+    wrapper.appendChild(overlay);
 
     for (let i = 0; i < searchMatches.length; i++) {
       const m = searchMatches[i];
@@ -1270,7 +1271,6 @@
 
   async function openFolder() {
     if (typeof window.electronAPI === 'undefined') return;
-    const { dialog } = require('electron');
     openFolderDialog();
   }
 
@@ -1308,17 +1308,13 @@
 
   function renderTree(tree, rootPath) {
     sidebarTree.innerHTML = '';
-    const rootNode = { name: path.basename(rootPath) || rootPath, path: rootPath, type: 'dir', children: tree };
+    const rootNode = { name: getFileName(rootPath) || rootPath, path: rootPath, type: 'dir', children: tree };
     expandedDirs.add(rootPath);
     const fragment = document.createDocumentFragment();
     buildTreeDOM(fragment, rootNode, 0);
     sidebarTree.appendChild(fragment);
   }
 
-  function pathBasename(p) {
-    return p.split(/[/\\]/).pop();
-  }
-
   function buildTreeDOM(parent, node, depth) {
     const item = document.createElement('div');
     item.className = 'tree-item';