release: 发布 v0.5.0

新增共享 Preview Engine，统一 Web 连续预览、快速分页、Playwright PDF 与 Electron PDF；实现稳定前缀复用和修改位置后的增量分页，保留媒体块按文档顺序串行回填与单次重排。

完善跨端链接与桌面文档工作流：Web 受控处理锚点和 HTTP/HTTPS 外链；Desktop 支持本地路径、file URI、系统协议、多窗口、同文件单例、Markdown 当前或新窗口打开，以及聚焦时外部文件变化提示。

统一四套内置主题名称并默认使用 Typora Github；修复连续预览双滚动条、ECharts 尺寸、PDF 本地链接、围栏代码块 Typora DOM 与重复行内样式；桌面发行链强制完整重建内嵌 Web，避免安装包携带陈旧资源。

发布 Web/Compose 与 Windows NSIS/ZIP：镜像 yixiong/md-to-pdf:v0.5.0 已健康部署；NSIS SHA-256 为 60992D1FDCA513F46346C78478537EB4159D8C0E76B41ECF3CDC25BE77707D92，ZIP SHA-256 为 D74F82293FB67126E583546CBA894569EFC9A0B1B6343FAC648CCC95F1D188D8，本机安装版已升级至 v0.5.0。

验证：全项目 238 项测试通过，类型检查、生产构建和 git diff --check 通过；Web 快速/连续/精确预览、Compose、Desktop 多窗口、窗口状态、文件关联、链接与代码块均完成真实环境验收。

apps/web/src/paged-preview-frame.ts

@@ -1,12 +1,15 @@
-import { PagedDocumentRuntime } from "./paged-document-runtime";
+import echartsCss from "@md-to-pdf/markdown-echarts/styles.css?inline";
 import {
   isPagedPreviewRenderRequest,
   PAGED_PREVIEW_MESSAGE_SCOPE,
+  PagedDocumentRuntime,
+  resolveMermaidOutputMode,
+  resolvePagedRenderTarget,
   type PagedPreviewFrameMessage,
   type PagedPreviewPayload
-} from "./paged-preview";
-import { resolvePagedRenderTarget } from "./paged-render-target";
-import { resolveMermaidOutputMode } from "./mermaid-static-image";
+} from "@md-to-pdf/preview-engine";
+import highlightCss from "highlight.js/styles/github.css?inline";
+import katexCss from "katex/dist/katex.min.css?inline";
 import {
   beginPreviewFrameRender,
   completePreviewFrameRender
@@ -23,7 +26,11 @@ function getPreviewRoot() {
 const previewRoot = getPreviewRoot();
 const renderTarget = resolvePagedRenderTarget(window.location.search);
 const mermaidOutput = resolveMermaidOutputMode(window.location.search);
-const runtime = new PagedDocumentRuntime(previewRoot);
+const runtime = new PagedDocumentRuntime(previewRoot, {
+  highlightCss,
+  katexCss,
+  echartsCss
+});
 document.documentElement.dataset.renderTarget = renderTarget;
 
 let latestRequestId = 0;
@@ -33,9 +40,47 @@ function post(message: PagedPreviewFrameMessage) {
   window.parent.postMessage(message, window.location.origin);
 }
 
+function measurePreviewContentHeight() {
+  const rootRect = previewRoot.getBoundingClientRect();
+  const documentRect =
+    document.documentElement.getBoundingClientRect();
+  return Math.ceil(
+    Math.max(
+      document.documentElement.scrollHeight,
+      document.body.scrollHeight,
+      previewRoot.scrollHeight,
+      rootRect.bottom - documentRect.top
+    )
+  );
+}
+
+document.addEventListener(
+  "click",
+  (event) => {
+    const target =
+      event.target instanceof Element
+        ? event.target.closest<HTMLAnchorElement>("a[href]")
+        : undefined;
+    const href = target?.getAttribute("href")?.trim();
+    if (!href) {
+      return;
+    }
+
+    event.preventDefault();
+    event.stopPropagation();
+    post({
+      scope: PAGED_PREVIEW_MESSAGE_SCOPE,
+      type: "link",
+      href
+    });
+  },
+  { capture: true }
+);
+
 async function renderPagedPreview(
   requestId: number,
-  payload: PagedPreviewPayload
+  payload: PagedPreviewPayload,
+  layout: "paged" | "continuous"
 ) {
   if (requestId !== latestRequestId) {
     return;
@@ -45,15 +90,21 @@ async function renderPagedPreview(
   post({
     scope: PAGED_PREVIEW_MESSAGE_SCOPE,
     type: "rendering",
-    requestId
+    requestId,
+    layout
   });
 
   try {
-    const result = await runtime.render(payload, {
-      target: renderTarget,
-      mermaidOutput,
-      shouldContinue: () => requestId === latestRequestId
-    });
+    const result =
+      layout === "continuous"
+        ? await runtime.renderContinuous(payload, {
+            shouldContinue: () => requestId === latestRequestId
+          })
+        : await runtime.render(payload, {
+            target: renderTarget,
+            mermaidOutput,
+            shouldContinue: () => requestId === latestRequestId
+          });
     if (!result) {
       return;
     }
@@ -62,7 +113,8 @@ async function renderPagedPreview(
       scope: PAGED_PREVIEW_MESSAGE_SCOPE,
       type: "rendered",
       requestId,
-      contentHeight: Math.ceil(document.documentElement.scrollHeight),
+      layout,
+      contentHeight: measurePreviewContentHeight(),
       ...result
     });
   } finally {
@@ -121,12 +173,12 @@ window.addEventListener("message", (event: MessageEvent<unknown>) => {
   }
 
   latestRequestId = Math.max(latestRequestId, event.data.requestId);
-  const { requestId, payload } = event.data;
+  const { requestId, layout, payload } = event.data;
   renderQueue = renderQueue
     .catch(() => undefined)
     .then(async () => {
       try {
-        await renderPagedPreview(requestId, payload);
+        await renderPagedPreview(requestId, payload, layout);
       } catch (reason: unknown) {
         if (requestId !== latestRequestId) {
           return;