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。

deploy/Dockerfile

@@ -13,6 +13,7 @@ COPY apps/web/package.json apps/web/package.json
 COPY packages/core/package.json packages/core/package.json
 COPY packages/application/package.json packages/application/package.json
 COPY packages/markdown-echarts/package.json packages/markdown-echarts/package.json
+COPY packages/preview-engine/package.json packages/preview-engine/package.json
 COPY packages/renderer/package.json packages/renderer/package.json
 RUN npm ci
 
@@ -24,6 +25,7 @@ RUN npm run build -w @md-to-pdf/markdown-echarts \
     && npm run build -w @md-to-pdf/core \
     && npm run build -w @md-to-pdf/renderer \
     && npm run build -w @md-to-pdf/application \
+    && npm run build -w @md-to-pdf/preview-engine \
     && npm run build -w @md-to-pdf/web \
     && npm run build -w @md-to-pdf/server
 
@@ -38,6 +40,7 @@ COPY apps/web/package.json apps/web/package.json
 COPY packages/core/package.json packages/core/package.json
 COPY packages/application/package.json packages/application/package.json
 COPY packages/markdown-echarts/package.json packages/markdown-echarts/package.json
+COPY packages/preview-engine/package.json packages/preview-engine/package.json
 COPY packages/renderer/package.json packages/renderer/package.json
 RUN npm ci --omit=dev --workspace @md-to-pdf/server --include-workspace-root
 
@@ -67,6 +70,7 @@ COPY --chown=pwuser:pwuser apps/web/package.json apps/web/package.json
 COPY --chown=pwuser:pwuser packages/core/package.json packages/core/package.json
 COPY --chown=pwuser:pwuser packages/application/package.json packages/application/package.json
 COPY --chown=pwuser:pwuser packages/markdown-echarts/package.json packages/markdown-echarts/package.json
+COPY --chown=pwuser:pwuser packages/preview-engine/package.json packages/preview-engine/package.json
 COPY --chown=pwuser:pwuser packages/renderer/package.json packages/renderer/package.json
 COPY --chown=pwuser:pwuser --from=production-dependencies /app/node_modules ./node_modules
 ENV PLAYWRIGHT_BROWSERS_PATH=/ms-playwright
@@ -83,6 +87,7 @@ COPY --chown=pwuser:pwuser --from=build /app/apps/web/dist ./apps/web/dist
 COPY --chown=pwuser:pwuser --from=build /app/packages/core/dist ./packages/core/dist
 COPY --chown=pwuser:pwuser --from=build /app/packages/application/dist ./packages/application/dist
 COPY --chown=pwuser:pwuser --from=build /app/packages/markdown-echarts/dist ./packages/markdown-echarts/dist
+COPY --chown=pwuser:pwuser --from=build /app/packages/preview-engine/dist ./packages/preview-engine/dist
 COPY --chown=pwuser:pwuser --from=build /app/packages/renderer/dist ./packages/renderer/dist
 COPY --chown=pwuser:pwuser themes ./themes
 COPY deploy/nginx.conf /etc/nginx/nginx.conf