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/pdf-annotation-links.ts

@@ -0,0 +1,152 @@
+import type { PDFDocumentProxy } from "pdfjs-dist";
+import { decodeLocalDocumentLinkFromPdf } from "@md-to-pdf/core";
+
+export type PdfDestination = string | unknown[];
+
+export interface PdfAnnotationLinkCallbacks {
+  onExternalLink: (href: string) => void;
+  onNavigateToPage: (pageNumber: number) => void;
+}
+
+export interface PdfAnnotationLinkService {
+  externalLinkEnabled: boolean;
+  addLinkAttributes(
+    link: HTMLAnchorElement,
+    url: string,
+    newWindow?: boolean
+  ): void;
+  getDestinationHash(destination: PdfDestination): string;
+  getAnchorUrl(anchor: string): string;
+  goToDestination(destination: PdfDestination): Promise<void>;
+  executeNamedAction(action: string): void;
+  executeSetOCGState(action: object): Promise<void>;
+  getAttachmentContent(id: string): Promise<undefined>;
+}
+
+export async function resolvePdfDestinationPage(
+  document: Pick<
+    PDFDocumentProxy,
+    "getDestination" | "getPageIndex" | "numPages"
+  >,
+  destination: PdfDestination
+) {
+  const explicitDestination =
+    typeof destination === "string"
+      ? await document.getDestination(destination)
+      : destination;
+  if (
+    !Array.isArray(explicitDestination) ||
+    explicitDestination.length === 0
+  ) {
+    return undefined;
+  }
+
+  const pageReference = explicitDestination[0];
+  let pageNumber: number;
+  if (
+    typeof pageReference === "number" &&
+    Number.isInteger(pageReference)
+  ) {
+    pageNumber = pageReference + 1;
+  } else if (
+    pageReference &&
+    typeof pageReference === "object"
+  ) {
+    pageNumber =
+      (await document.getPageIndex(
+        pageReference as Parameters<
+          PDFDocumentProxy["getPageIndex"]
+        >[0]
+      )) + 1;
+  } else {
+    return undefined;
+  }
+
+  return pageNumber >= 1 && pageNumber <= document.numPages
+    ? pageNumber
+    : undefined;
+}
+
+export function resolvePdfNamedActionPage(
+  action: string,
+  currentPage: number,
+  pageCount: number
+) {
+  switch (action) {
+    case "FirstPage":
+      return 1;
+    case "LastPage":
+      return pageCount;
+    case "NextPage":
+    case "PageDown":
+      return Math.min(pageCount, currentPage + 1);
+    case "PrevPage":
+    case "PageUp":
+      return Math.max(1, currentPage - 1);
+    default:
+      return undefined;
+  }
+}
+
+export function createPdfAnnotationLinkService(
+  document: Pick<
+    PDFDocumentProxy,
+    "getDestination" | "getPageIndex" | "numPages"
+  >,
+  currentPage: number,
+  callbacks: PdfAnnotationLinkCallbacks
+): PdfAnnotationLinkService {
+  return {
+    externalLinkEnabled: true,
+    addLinkAttributes(link, url) {
+      const resolvedUrl =
+        decodeLocalDocumentLinkFromPdf(url) ?? url;
+      link.href = "#";
+      link.rel = "noopener noreferrer";
+      link.title ||= resolvedUrl;
+      link.dataset.pdfExternalHref = resolvedUrl;
+      link.onclick = (event) => {
+        event.preventDefault();
+        event.stopPropagation();
+        callbacks.onExternalLink(resolvedUrl);
+        return false;
+      };
+    },
+    getDestinationHash() {
+      return "#pdf-destination";
+    },
+    getAnchorUrl() {
+      return "#pdf-action";
+    },
+    async goToDestination(destination) {
+      try {
+        const pageNumber = await resolvePdfDestinationPage(
+          document,
+          destination
+        );
+        if (pageNumber !== undefined) {
+          callbacks.onNavigateToPage(pageNumber);
+        }
+      } catch {
+        // 损坏或无法解析的 PDF 目标保持无行为。
+      }
+    },
+    executeNamedAction(action) {
+      const pageNumber = resolvePdfNamedActionPage(
+        action,
+        currentPage,
+        document.numPages
+      );
+      if (pageNumber !== undefined) {
+        callbacks.onNavigateToPage(pageNumber);
+      }
+    },
+    async executeSetOCGState() {
+      // 精确预览不改变 PDF 可选内容组状态。
+    },
+    async getAttachmentContent() {
+      // 精确预览不下载或执行 PDF 内嵌附件。
+      return undefined;
+    }
+  };
+}