v0.3.10: 全面优化增强 — 17项Bug修复/稳定性/功能改进

P0 致命Bug修复:
- A1: openFolderDialog 类型/运行时崩溃(文件夹打开功能完全失效)
- A2: SourceEditor 受控textarea手动改DOM反模式
- A3: tabStore.updateTabContent 内容相同时误标isModified

死代码清理:
- B1: 删除menu:*/save/as/viewMode 三个永不触发的IPC通道

健壮性修复:
- E1: rehypeFixImages 路径规范化+防越界加固
- E2: getFileName 尾斜杠返回正确文件名
- E3: EditorToolbar 行内代码按钮改用toggleInlineCodeCommand
- E4: ErrorBoundary 内联样式抽为CSS类

功能增强:
- D1: 标签页拖拽排序(tabStore.moveTab + TabBar DnD + CSS)
- D2: Milkdown自动配对括号/引号(ProseMirror插件)
- D3: 状态栏自动保存开关可点击
- D4: 文档大纲活跃标题高亮(useActiveHeading hook)
- D5: 关闭窗口前flush防抖数据(flushSaveToDB)
- D6: 搜索替换支持正则表达式

类型/架构:
- C2: preload类型集中定义(ElectronAPI契约)
- __pycache__ typo修复

文档/版本:
- README/DESIGN同步为Milkdown + v0.3.10
- 项目结构树/技术栈/快捷键表更新

验证: typecheck(仅7预存), lint✅, test 96/96, vite build✅

src/renderer/hooks/useActiveHeading.ts

@@ -0,0 +1,82 @@
+import { useEffect, useRef, useState, useCallback } from 'react'
+
+/**
+ * D4: 基于视口的活跃标题追踪 hook
+ * 在 preview 模式下监听目标容器的滚动事件，
+ * 根据文档中标题元素的 offsetTop 判断当前可见的标题索引。
+ *
+ * 仅在目标容器 ref 存在时生效（preview 面板挂载后）。
+ *
+ * @param containerRef - 包含 Markdown 渲染结果的 DOM 元素 ref
+ * @param headings    - 解析出的标题列表
+ * @returns           - 当前活跃标题的索引（null 表示无法判定或不在范围内）
+ */
+export function useActiveHeading(
+  containerRef: React.RefObject<HTMLElement | null>,
+  headings: { level: number; text: string }[]
+): number | null {
+  const [activeIndex, setActiveIndex] = useState<number | null>(null)
+  const observerRef = useRef<IntersectionObserver | null>(null)
+
+  const handleScroll = useCallback(() => {
+    const container = containerRef.current
+    if (!container || headings.length === 0) {
+      setActiveIndex(null)
+      return
+    }
+
+    // 收集容器内所有 h1-h6 元素的 offsetTop
+    const headingElements = Array.from(
+      container.querySelectorAll('h1, h2, h3, h4, h5, h6')
+    ) as HTMLElement[]
+
+    if (headingElements.length === 0) {
+      setActiveIndex(null)
+      return
+    }
+
+    const scrollTop = container.scrollTop
+    const containerHeight = container.clientHeight
+    const threshold = scrollTop + containerHeight * 0.3 // 上方 30% 位置视为"到达"
+
+    let bestIndex: number | null = null
+
+    for (let i = 0; i < headingElements.length; i++) {
+      const el = headingElements[i]
+      // 使用容器顶部的相对偏移而非 getBoundingClientRect（滚动容器不是 window）
+      const top = el.offsetTop - (container.offsetTop || 0)
+      if (top <= threshold) {
+        // 找到 headings 中匹配的索引
+        const text = el.textContent?.trim() ?? ''
+        const matchIdx = headings.findIndex(
+          h => h.text.trim() === text && el.tagName.slice(-1) === String(h.level)
+        )
+        if (matchIdx >= 0) bestIndex = matchIdx
+      }
+    }
+
+    setActiveIndex(bestIndex)
+  }, [containerRef, headings])
+
+  useEffect(() => {
+    const container = containerRef.current
+    if (!container || headings.length === 0) {
+      setActiveIndex(null)
+      return
+    }
+
+    // 监听滚动事件
+    container.addEventListener('scroll', handleScroll, { passive: true })
+
+    // 初始计算
+    handleScroll()
+
+    const observer = observerRef.current
+    return () => {
+      container.removeEventListener('scroll', handleScroll)
+      observer?.disconnect()
+    }
+  }, [containerRef, headings, handleScroll])
+
+  return activeIndex
+}

src/renderer/hooks/useFolderOperations.ts

@@ -15,22 +15,19 @@ export function useFolderOperations() {
 
   const handleOpenFolder = useCallback(async () => {
     if (!window.electronAPI) return
-    const result = await window.electronAPI.openFolderDialog()
-    if (!result) return
-    if (!result.canceled && result.filePaths[0]) {
-      const dirPath = result.filePaths[0]
-      setRootPath(dirPath)
-      expandDirs([dirPath])
-      setLoading('dir-load', true)
-      try {
-        const dirTree = await window.electronAPI.readDirTree(dirPath)
-        if (dirTree.success && dirTree.tree) {
-          setTree(dirTree.tree)
-          window.electronAPI.watchDir(dirPath)
-        }
-      } finally {
-        setLoading('dir-load', false)
+    const dirPath = await window.electronAPI.openFolderDialog()
+    if (!dirPath) return
+    setRootPath(dirPath)
+    expandDirs([dirPath])
+    setLoading('dir-load', true)
+    try {
+      const dirTree = await window.electronAPI.readDirTree(dirPath)
+      if (dirTree.success && dirTree.tree) {
+        setTree(dirTree.tree)
+        window.electronAPI.watchDir(dirPath)
       }
+    } finally {
+      setLoading('dir-load', false)
     }
   }, [setRootPath, setTree, expandDirs, setLoading])
 

src/renderer/hooks/useIpcListeners.ts

@@ -1,17 +1,13 @@
-import { useEffect, useRef } from 'react'
+import { useEffect } from 'react'
 import { useTabStore } from '../stores/tabStore'
 import { recentFilesRepository } from '../db/recentFilesRepository'
 
 /**
  * 主进程事件注册 hook
- * 处理菜单触发的文件打开、保存、另存为事件
+ * 处理通过命令行或文件关联打开的文件
  */
-export function useIpcListeners(handleSave: () => void, handleSaveAs: () => void) {
+export function useIpcListeners() {
   const createTab = useTabStore(s => s.createTab)
-  const handleSaveRef = useRef(handleSave)
-  const handleSaveAsRef = useRef(handleSaveAs)
-  handleSaveRef.current = handleSave
-  handleSaveAsRef.current = handleSaveAs
 
   useEffect(() => {
     if (!window.electronAPI) return
@@ -21,9 +17,6 @@ export function useIpcListeners(handleSave: () => void, handleSaveAs: () => void
       if (data.filePath) recentFilesRepository.add(data.filePath)
       setTimeout(() => useTabStore.getState().saveToDB(), 100)
     }
-    const unsub1 = api.onFileOpenInTab(onOpen)
-    const unsub2 = api.onMenuSave(() => handleSaveRef.current())
-    const unsub3 = api.onMenuSaveAs(() => handleSaveAsRef.current())
-    return () => { unsub1(); unsub2(); unsub3() }
+    return api.onFileOpenInTab(onOpen)
   }, [createTab])
 }

src/renderer/hooks/useUnsavedWarning.ts

@@ -6,10 +6,14 @@ import { useEffect, useCallback, useRef } from 'react'
  */
 export function useUnsavedWarning(
   hasUnsaved: () => boolean,
-  confirmFn?: (message: string) => Promise<boolean>
+  confirmFn?: (message: string) => Promise<boolean>,
+  // D5: 关闭前回调（flush 待保存数据）
+  onBeforeForceClose?: () => Promise<void>
 ) {
   const confirmFnRef = useRef(confirmFn)
   confirmFnRef.current = confirmFn
+  const onBeforeForceCloseRef = useRef(onBeforeForceClose)
+  onBeforeForceCloseRef.current = onBeforeForceClose
 
   const doConfirm = useCallback(async (message: string): Promise<boolean> => {
     if (confirmFnRef.current) {
@@ -35,11 +39,13 @@ export function useUnsavedWarning(
 
     const unsubscribe = api.onConfirmClose(async () => {
       if (!hasUnsaved()) {
+        await onBeforeForceCloseRef.current?.()
         api.forceClose()
         return
       }
       const shouldClose = await doConfirm('有文件尚未保存，确定要关闭吗？')
       if (shouldClose) {
+        await onBeforeForceCloseRef.current?.()
         api.forceClose()
       } else {
         api.cancelClose()