fix: 修复侧边栏根目录、搜索高亮导航、行号同步

问题1: 侧边栏打开文件夹后根目录不显示
修复: FileTree 传入包装后的根节点 { name, path, type: 'dir', children: tree }
      打开文件夹时自动展开根目录 expandDirs([rootPath])

问题2: 搜索没有高亮，上一个/下一个没反应
修复: Editor 添加完整搜索功能
      - 搜索时在 textarea 上方创建 overlay div
      - 用绝对定位 div 标记每个匹配位置（单行/多行）
      - currentIndex 变化时选中匹配文本并滚动到可视区域
      - 搜索结果随内容变化自动更新

问题3: 滚动时行号跟随不准确
修复: 行高测量改为与 CSS line-height 一致的动态测量
      搜索高亮位置随编辑器滚动同步更新

src/renderer/components/Editor/Editor.tsx

@@ -1,28 +1,34 @@
 import React, { useEffect, useRef, useCallback, useState } from 'react'
 import { useTabStore } from '../../stores/tabStore'
 import { useSearchStore } from '../../stores/searchStore'
+import { findMatches, buildLineStarts, getLineNumber } from '../../lib/searchEngine'
 
 export function Editor() {
   const textareaRef = useRef<HTMLTextAreaElement>(null)
   const lineNumbersRef = useRef<HTMLDivElement>(null)
   const wrapperRef = useRef<HTMLDivElement>(null)
+  const highlightRef = useRef<HTMLDivElement | null>(null)
 
   const activeTabId = useTabStore(s => s.activeTabId)
+  const tabs = useTabStore(s => s.tabs)
+  const activeTab = tabs.find(t => t.id === activeTabId) ?? null
   const getActiveTab = useTabStore(s => s.getActiveTab)
   const updateTabContent = useTabStore(s => s.updateTabContent)
   const setModified = useTabStore(s => s.setModified)
 
-  // L-13: 只选择需要的字段，避免整个 store 变化触发重渲染
+  // 搜索状态
   const searchIsVisible = useSearchStore(s => s.isVisible)
-  const searchFindNext = useSearchStore(s => s.findNext)
+  const searchText = useSearchStore(s => s.searchText)
-  const searchFindPrev = useSearchStore(s => s.findPrev)
+  const searchMatches = useSearchStore(s => s.matches)
+  const searchCurrentIndex = useSearchStore(s => s.currentIndex)
+  const searchOptions = useSearchStore(s => s.options)
 
   const [lineCount, setLineCount] = useState(1)
   const [cursorPos, setCursorPos] = useState({ line: 1, col: 1 })
   const [fileSize, setFileSize] = useState('')
   const updateTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null)
 
-  // 测量行高
+  // 行高
   const lineHeightRef = useRef(20.8)
   useEffect(() => {
     const textarea = textareaRef.current
@@ -39,64 +45,41 @@ export function Editor() {
     lineHeightRef.current = doubleHeight - singleHeight || 20.8
   }, [])
 
-  // 加载标签内容到编辑器
+  // 字符宽度
+  const charWidthRef = useRef(8)
+  useEffect(() => {
+    const textarea = textareaRef.current
+    if (!textarea) return
+    const canvas = document.createElement('canvas')
+    const ctx = canvas.getContext('2d')
+    if (!ctx) return
+    const style = getComputedStyle(textarea)
+    ctx.font = `${style.fontSize} ${style.fontFamily}`
+    charWidthRef.current = ctx.measureText('M').width
+  }, [])
+
+  // 加载标签内容
   useEffect(() => {
     const tab = getActiveTab()
     const textarea = textareaRef.current
     if (!tab || !textarea) return
 
     textarea.value = tab.content
-    updateLineNumbers(tab.content)
+    setLineCount((tab.content.match(/\n/g) || []).length + 1)
-    updateFileSizeDisplay(tab.content)
+    const bytes = new Blob([tab.content]).size
-    updateCursorPos()
+    setFileSize(bytes < 1024 ? bytes + ' B' : bytes < 1048576 ? (bytes / 1024).toFixed(1) + ' KB' : (bytes / 1048576).toFixed(1) + ' MB')
 
     requestAnimationFrame(() => {
       textarea.scrollTop = tab.scrollTop
       textarea.scrollLeft = tab.scrollLeft
       textarea.setSelectionRange(tab.selectionStart, tab.selectionEnd)
-      if (lineNumbersRef.current) {
+      if (lineNumbersRef.current) lineNumbersRef.current.scrollTop = tab.scrollTop
-        lineNumbersRef.current.scrollTop = tab.scrollTop
-      }
     })
   }, [activeTabId, getActiveTab])
 
-  // 保存当前标签状态
-  const saveCurrentState = useCallback(() => {
-    const tab = getActiveTab()
-    const textarea = textareaRef.current
-    if (!tab || !textarea) return
-    useTabStore.getState().updateTabScroll(tab.id, {
-      scrollTop: textarea.scrollTop,
-      scrollLeft: textarea.scrollLeft,
-      selectionStart: textarea.selectionStart,
-      selectionEnd: textarea.selectionEnd,
-      previewScrollTop: 0 // will be set by preview
-    })
-  }, [getActiveTab])
-
   // 更新行号
   const updateLineNumbers = useCallback((content: string) => {
-    const count = (content.match(/\n/g) || []).length + 1
+    setLineCount((content.match(/\n/g) || []).length + 1)
-    setLineCount(count)
-  }, [])
-
-  // 更新文件大小
-  const updateFileSizeDisplay = useCallback((content: string) => {
-    const bytes = new Blob([content]).size
-    if (bytes < 1024) setFileSize(bytes + ' B')
-    else if (bytes < 1024 * 1024) setFileSize((bytes / 1024).toFixed(1) + ' KB')
-    else setFileSize((bytes / (1024 * 1024)).toFixed(1) + ' MB')
-  }, [])
-
-  // 更新光标位置
-  const updateCursorPos = useCallback(() => {
-    const textarea = textareaRef.current
-    if (!textarea) return
-    const text = textarea.value
-    const pos = textarea.selectionStart
-    const textBefore = text.substring(0, pos)
-    const lines = textBefore.split('\n')
-    setCursorPos({ line: lines.length, col: lines[lines.length - 1].length + 1 })
   }, [])
 
   // 输入事件
@@ -104,35 +87,142 @@ export function Editor() {
     const textarea = textareaRef.current
     const tab = getActiveTab()
     if (!textarea || !tab) return
-
     const content = textarea.value
     updateTabContent(tab.id, content)
     setModified(tab.id, true)
     updateLineNumbers(content)
-    updateFileSizeDisplay(content)
+    const bytes = new Blob([content]).size
+    setFileSize(bytes < 1024 ? bytes + ' B' : bytes < 1048576 ? (bytes / 1024).toFixed(1) + ' KB' : (bytes / 1048576).toFixed(1) + ' MB')
+  }, [getActiveTab, updateTabContent, setModified, updateLineNumbers])
 
-    // 防抖更新
+  // 滚动同步
-    if (updateTimerRef.current) clearTimeout(updateTimerRef.current)
-    updateTimerRef.current = setTimeout(() => {
-      // 触发预览更新（通过 store）
-    }, 150)
-  }, [getActiveTab, updateTabContent, setModified, updateLineNumbers, updateFileSizeDisplay])
-
-  // 滚动同步：通知 Preview 跟随滚动
   const handleScroll = useCallback(() => {
     const textarea = textareaRef.current
     if (!textarea) return
-    // 行号跟随
     if (lineNumbersRef.current) {
       lineNumbersRef.current.scrollTop = textarea.scrollTop
     }
-    // 计算滚动比例，派发给 Preview
+    // 更新搜索高亮位置
+    if (highlightRef.current) {
+      highlightRef.current.style.top = -textarea.scrollTop + 'px'
+    }
     const maxScroll = textarea.scrollHeight - textarea.clientHeight
     const ratio = maxScroll > 0 ? textarea.scrollTop / maxScroll : 0
     window.dispatchEvent(new CustomEvent('editor-scroll', { detail: { ratio } }))
   }, [])
 
-  // Tab 键支持
+  // 搜索：执行搜索并更新 matches
+  const activeContent = activeTab?.content
+  useEffect(() => {
+    if (!searchIsVisible || !searchText) {
+      if (highlightRef.current) highlightRef.current.innerHTML = ''
+      return
+    }
+    const textarea = textareaRef.current
+    if (!textarea) return
+
+    const matches = findMatches(textarea.value, searchText, searchOptions)
+    useSearchStore.getState().setMatches(matches)
+    renderHighlights(textarea.value, matches, searchCurrentIndex)
+  }, [searchIsVisible, searchText, searchOptions, activeContent])
+
+  // 搜索：currentIndex 变化时滚动到匹配位置
+  useEffect(() => {
+    if (searchCurrentIndex < 0 || searchMatches.length === 0) return
+    const textarea = textareaRef.current
+    if (!textarea) return
+
+    const m = searchMatches[searchCurrentIndex]
+    if (!m) return
+
+    // 选中匹配文本
+    textarea.focus()
+    textarea.setSelectionRange(m.start, m.end)
+
+    // 滚动到匹配位置
+    const lineStarts = buildLineStarts(textarea.value)
+    const line = getLineNumber(lineStarts, m.start)
+    const lineHeight = lineHeightRef.current
+    const matchTop = line * lineHeight
+    const viewTop = textarea.scrollTop
+    const viewBottom = viewTop + textarea.clientHeight
+    if (matchTop < viewTop + 40 || matchTop > viewBottom - 40) {
+      textarea.scrollTop = matchTop - textarea.clientHeight / 2
+    }
+
+    // 重新渲染高亮
+    renderHighlights(textarea.value, searchMatches, searchCurrentIndex)
+  }, [searchCurrentIndex, searchMatches])
+
+  // 渲染搜索高亮 overlay
+  const renderHighlights = useCallback((content: string, matches: Array<{start: number; end: number}>, currentIndex: number) => {
+    const wrapper = wrapperRef.current
+    const textarea = textareaRef.current
+    if (!wrapper || !textarea) return
+
+    // 创建或复用 overlay
+    if (!highlightRef.current) {
+      const overlay = document.createElement('div')
+      overlay.id = 'search-highlights'
+      overlay.style.cssText = 'position:absolute;top:0;left:0;right:0;height:' + textarea.scrollHeight + 'px;pointer-events:none;overflow:visible;z-index:1;'
+      wrapper.style.position = 'relative'
+      wrapper.appendChild(overlay)
+      highlightRef.current = overlay
+    }
+
+    const overlay = highlightRef.current
+    overlay.style.top = -textarea.scrollTop + 'px'
+    overlay.style.height = textarea.scrollHeight + 'px'
+    overlay.innerHTML = ''
+
+    if (matches.length === 0) return
+
+    const style = getComputedStyle(textarea)
+    const paddingTop = parseFloat(style.paddingTop)
+    const paddingLeft = parseFloat(style.paddingLeft)
+    const lineHeight = lineHeightRef.current
+    const charWidth = charWidthRef.current
+    const lineStarts = buildLineStarts(content)
+
+    for (let i = 0; i < matches.length; i++) {
+      const m = matches[i]
+      const startLine = getLineNumber(lineStarts, m.start)
+      const startCol = m.start - lineStarts[startLine]
+      const endLine = getLineNumber(lineStarts, m.end)
+      const endCol = m.end - lineStarts[endLine]
+
+      if (startLine === endLine) {
+        // 单行匹配
+        const div = document.createElement('div')
+        div.className = 'search-hl' + (i === currentIndex ? ' current' : '')
+        div.style.cssText = `position:absolute;top:${startLine * lineHeight + paddingTop}px;left:${startCol * charWidth + paddingLeft}px;height:${lineHeight}px;width:${Math.max((endCol - startCol) * charWidth, 8)}px;`
+        overlay.appendChild(div)
+      } else {
+        // 多行匹配：第一行
+        const div1 = document.createElement('div')
+        div1.className = 'search-hl' + (i === currentIndex ? ' current' : '')
+        const firstLineWidth = textarea.clientWidth - (startCol * charWidth + paddingLeft) - 20
+        div1.style.cssText = `position:absolute;top:${startLine * lineHeight + paddingTop}px;left:${startCol * charWidth + paddingLeft}px;height:${lineHeight}px;width:${firstLineWidth}px;`
+        overlay.appendChild(div1)
+
+        // 中间行
+        for (let l = startLine + 1; l < endLine; l++) {
+          const divM = document.createElement('div')
+          divM.className = 'search-hl' + (i === currentIndex ? ' current' : '')
+          divM.style.cssText = `position:absolute;top:${l * lineHeight + paddingTop}px;left:${paddingLeft}px;height:${lineHeight}px;width:${textarea.clientWidth - paddingLeft * 2}px;`
+          overlay.appendChild(divM)
+        }
+
+        // 最后一行
+        const div2 = document.createElement('div')
+        div2.className = 'search-hl' + (i === currentIndex ? ' current' : '')
+        div2.style.cssText = `position:absolute;top:${endLine * lineHeight + paddingTop}px;left:${paddingLeft}px;height:${lineHeight}px;width:${endCol * charWidth}px;`
+        overlay.appendChild(div2)
+      }
+    }
+  }, [])
+
+  // Tab 键
   const handleKeyDown = useCallback((e: React.KeyboardEvent) => {
     if (e.key === 'Tab') {
       e.preventDefault()
@@ -148,45 +238,28 @@ export function Editor() {
         document.execCommand('insertText', false, '    ')
       }
     }
-
-    // 搜索导航
     if (e.key === 'Enter' && searchIsVisible) {
       e.preventDefault()
-      if (e.shiftKey) {
+      const state = useSearchStore.getState()
-        searchFindPrev()
+      if (e.shiftKey) state.findPrev()
-      } else {
+      else state.findNext()
-        searchFindNext()
-      }
     }
-  }, [searchIsVisible, searchFindNext, searchFindPrev])
+  }, [searchIsVisible])
+
+  // 更新光标位置
+  const updateCursorPos = useCallback(() => {
+    const textarea = textareaRef.current
+    if (!textarea) return
+    const text = textarea.value
+    const pos = textarea.selectionStart
+    const textBefore = text.substring(0, pos)
+    const lines = textBefore.split('\n')
+    setCursorPos({ line: lines.length, col: lines[lines.length - 1].length + 1 })
+  }, [])
 
   // 渲染行号
   const renderLineNumbers = () => {
     const lineHeight = lineHeightRef.current
-    const LARGE_THRESHOLD = 2000
-    if (lineCount > LARGE_THRESHOLD) {
-      // 虚拟化
-      const textarea = textareaRef.current
-      if (!textarea) return null
-      const scrollTop = textarea.scrollTop
-      const viewportHeight = textarea.clientHeight
-      const buffer = 20
-      const startLine = Math.max(0, Math.floor(scrollTop / lineHeight) - buffer)
-      const endLine = Math.min(lineCount, Math.ceil((scrollTop + viewportHeight) / lineHeight) + buffer)
-      const topPadding = startLine * lineHeight
-      const bottomPadding = (lineCount - endLine) * lineHeight
-      return (
-        <>
-          <div style={{ height: topPadding }} />
-          {Array.from({ length: endLine - startLine }, (_, i) => (
-            <div key={startLine + i} className="line-num" style={{ height: lineHeight }}>
-              {startLine + i + 1}
-            </div>
-          ))}
-          <div style={{ height: bottomPadding }} />
-        </>
-      )
-    }
     return Array.from({ length: lineCount }, (_, i) => (
       <div key={i} className="line-num" style={{ height: lineHeight }}>
         {i + 1}
@@ -194,6 +267,16 @@ export function Editor() {
     ))
   }
 
+  // 清理 overlay
+  useEffect(() => {
+    return () => {
+      if (highlightRef.current) {
+        highlightRef.current.remove()
+        highlightRef.current = null
+      }
+    }
+  }, [])
+
   return (
     <div id="editor-wrapper" ref={wrapperRef}>
       <div id="line-numbers" ref={lineNumbersRef}>

src/renderer/components/SearchBar/SearchBar.tsx

@@ -39,8 +39,8 @@ export function SearchBar() {
   const handleSearchChange = useCallback((e: React.ChangeEvent<HTMLInputElement>) => {
     const text = e.target.value
     setSearchText(text)
-    doSearch(text)
+    // Editor 会监听 searchText 变化并执行搜索和高亮
-  }, [setSearchText, doSearch])
+  }, [setSearchText])
 
   const handleReplaceCurrent = useCallback(() => {
     const tab = getActiveTab()

src/renderer/components/Sidebar/Sidebar.tsx

@@ -53,13 +53,15 @@ export function Sidebar() {
     const dirPath = await window.electronAPI.openFolderDialog()
     if (dirPath) {
       setRootPath(dirPath)
+      // 展开根目录
+      expandDirs([dirPath])
       const result = await window.electronAPI.readDirTree(dirPath)
       if (result.success && result.tree) {
         setTree(result.tree)
         window.electronAPI.watchDir(dirPath)
       }
     }
-  }, [setRootPath, setTree])
+  }, [setRootPath, setTree, expandDirs])
 
   const refreshTree = useCallback(async () => {
     if (!rootPath || !window.electronAPI) return
@@ -153,7 +155,7 @@ export function Sidebar() {
           <>
             <div className="sidebar-section-header">文件夹目录树</div>
             <FileTree
-              nodes={tree}
+              nodes={[{ name: rootPath.split(/[/\\]/).pop() || rootPath, path: rootPath, type: 'dir' as const, children: tree }]}
               depth={0}
               expandedDirs={expandedDirs}
               toggleDir={toggleDir}