feat: v0.4.3 — 浮动工具栏定位引擎重做 + 程序化编辑统一刷新管线

- 浮动工具栏 mirror 镜像测量：隐藏镜像层复制 textarea 排版样式，选区锚点插零宽字符读像素坐标，CJK/软换行/跨行选区误差全部消除

- 实测尺寸替代魔法数字；滚动 rAF 节流重定位；滚出视口自动隐藏；a11y：role=toolbar + aria-label、visibility 移出 Tab 序列、键盘可达

- 修复死开关/监听器泄漏/销毁后 focus 崩溃/blur 焦点抖动误隐藏

- _afterProgrammaticEdit 统一 8 条程序化路径的渲染/行号/字数/大纲/事件刷新；右键菜单 label 转义、copyAsHTML Firefox 降级、paste 失败提示、Esc 退出全屏

- 测试 871 → 895，e2e 22 → 28 项断言（含真实浏览器浮动工具栏布局验证）

site/index.html

@@ -4,7 +4,7 @@
 <meta charset="UTF-8"/>
 <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
 <link rel="icon" href="data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'><text y='.9em' font-size='90'>🚀</text></svg>"/>
-<title>MetonaEditor v0.4.2 · TypeScript · 桌面端 Markdown 编辑器</title>
+<title>MetonaEditor v0.4.3 · TypeScript · 桌面端 Markdown 编辑器</title>
 <style>
 *{box-sizing:border-box;margin:0;padding:0}
 :root{--bg:#0f1117;--bg-soft:#161922;--card:#1c2029;--card-hover:#232834;--text:#e6e8eb;--muted:#9ca3af;--accent:#3b82f6;--accent-2:#8b5cf6;--accent-3:#ec4899;--accent-soft:rgba(59,130,246,.12);--border:rgba(255,255,255,.08);--gradient:linear-gradient(135deg,#3b82f6 0%,#8b5cf6 50%,#ec4899 100%);--shadow:0 20px 50px -20px rgba(0,0,0,.5)}
@@ -106,10 +106,10 @@ footer a:hover{text-decoration:underline}
   <h1>TypeScript 重构 · 零依赖<br/><span class="grad">桌面端 Markdown 编辑器</span></h1>
   <p class="tagline">全模块 TypeScript 严格模式，内置自研解析器（99% 行覆盖率），6 个预设插件，中文优先。为桌面端现代 Web 应用而生。</p>
   <div class="badges">
-    <span class="badge accent">v0.4.2</span>
+    <span class="badge accent">v0.4.3</span>
     <span class="badge">TypeScript</span>
     <span class="badge">零运行时依赖</span>
-    <span class="badge">871 tests</span>
+    <span class="badge">895 tests</span>
     <span class="badge">桌面端优先</span>
     <span class="badge">MIT</span>
   </div>
@@ -120,7 +120,7 @@ footer a:hover{text-decoration:underline}
   <div class="stats">
     <div class="stat"><div class="stat-num">0</div><div class="stat-label">运行时依赖</div></div>
     <div class="stat"><div class="stat-num">99%</div><div class="stat-label">解析器行覆盖</div></div>
-    <div class="stat"><div class="stat-num">871</div><div class="stat-label">单元测试</div></div>
+    <div class="stat"><div class="stat-num">895</div><div class="stat-label">单元测试</div></div>
     <div class="stat"><div class="stat-num">~42KB</div><div class="stat-label">gzip 体积</div></div>
   </div>
 </header>
@@ -147,7 +147,7 @@ footer a:hover{text-decoration:underline}
       <div class="feature"><div class="feature-icon"><svg width="22" height="22" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="5"/><line x1="12" y1="1" x2="12" y2="3"/><line x1="12" y1="21" x2="12" y2="23"/><line x1="4.22" y1="4.22" x2="5.64" y2="5.64"/><line x1="18.36" y1="18.36" x2="19.78" y2="19.78"/><line x1="1" y1="12" x2="3" y2="12"/><line x1="21" y1="12" x2="23" y2="12"/></svg></div><h3>主题 & i18n</h3><p>4 套预设主题 + CSS 变量定制 + 实例级隔离。六种语言开箱即用（中 / 英 / 日 / 韩 / 法 / 德），支持远程加载翻译包。</p></div>
       <div class="feature"><div class="feature-icon"><svg width="22" height="22" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polyline points="16 18 22 12 16 6"/><polyline points="8 6 2 12 8 18"/></svg></div><h3>内置语法高亮</h3><p>零依赖轻量高亮器，js / ts / python / bash / css 等 16 个语言标识，代码块一行配置即自动着色。</p></div>
       <div class="feature"><div class="feature-icon"><svg width="22" height="22" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M12 22s8-4 8-10V5l-8-3-8 3v7c0 6 8 10 8 10z"/></svg></div><h3>XSS 安全防护</h3><p>HTML 转义、危险协议过滤、属性级注入防护、sanitize 钩子、highlight 异常回退。多层防护，安全可靠。</p></div>
-      <div class="feature"><div class="feature-icon"><svg width="22" height="22" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polyline points="13 2 3 14 12 14 11 22 21 10 12 10 13 2"/></svg></div><h3>性能与工程</h3><p>字数/词数/行数差异增量统计、高亮规则缓存、大纲 O(n) 构建；871 单测 + Playwright 真实浏览器冒烟，CI 并行 5 job。</p></div>
+      <div class="feature"><div class="feature-icon"><svg width="22" height="22" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polyline points="13 2 3 14 12 14 11 22 21 10 12 10 13 2"/></svg></div><h3>性能与工程</h3><p>字数/词数/行数差异增量统计、高亮规则缓存、大纲 O(n) 构建；895 单测 + Playwright 真实浏览器冒烟，CI 并行 5 job。</p></div>
     </div>
   </div>
 </section>
@@ -230,7 +230,7 @@ editor<span class="c-punc">.</span><span class="c-fn">exec</span><span class="c-
       <a href="https://git.metona.cn/MetonaTeam/MetonaEditor" target="_blank" rel="noopener">源码仓库</a>
       <a href="https://git.metona.cn/MetonaTeam/MetonaEditor/issues" target="_blank" rel="noopener">问题反馈</a>
     </div>
-    <div>MetonaEditor v0.4.2 · TypeScript · MIT License · MetonaTeam</div>
+    <div>MetonaEditor v0.4.3 · TypeScript · MIT License · MetonaTeam</div>
   </div>
 </footer>
 
@@ -240,7 +240,7 @@ MeEditor.themes.switchTheme('dark');
 MeEditor.create('#editor', {
   mode: 'split', height: 480, theme: 'dark',
   value: [
-    '# 欢迎使用 MetonaEditor v0.4.2',
+    '# 欢迎使用 MetonaEditor v0.4.3',
     '',
     '一个 **TypeScript 重构 · 零运行时依赖** 的桌面端 Markdown 编辑器。',
     '',