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。

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "md-to-pdf",
-  "version": "0.4.5",
+  "version": "0.5.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "md-to-pdf",
-      "version": "0.4.5",
+      "version": "0.5.0",
       "workspaces": [
         "apps/*",
         "packages/*"
@@ -21,7 +21,7 @@
     },
     "apps/desktop": {
       "name": "@md-to-pdf/desktop",
-      "version": "0.4.5",
+      "version": "0.5.0",
       "devDependencies": {
         "@md-to-pdf/application": "0.4.1",
         "@types/node": "^24.10.1",
@@ -539,11 +539,9 @@
       "dependencies": {
         "@md-to-pdf/core": "0.1.0",
         "@md-to-pdf/markdown-echarts": "0.1.0",
-        "@mermaid-js/layout-elk": "0.2.2",
+        "@md-to-pdf/preview-engine": "0.1.0",
         "highlight.js": "^11.11.1",
         "katex": "^0.16.28",
-        "mermaid": "11.16.0",
-        "pagedjs": "^0.4.3",
         "pdfjs-dist": "6.1.200",
         "react": "^19.2.0",
         "react-dom": "^19.2.0"
@@ -1956,6 +1954,10 @@
       "resolved": "packages/markdown-echarts",
       "link": true
     },
+    "node_modules/@md-to-pdf/preview-engine": {
+      "resolved": "packages/preview-engine",
+      "link": true
+    },
     "node_modules/@md-to-pdf/renderer": {
       "resolved": "packages/renderer",
       "link": true
@@ -5505,7 +5507,6 @@
       "version": "6.1.0",
       "resolved": "https://registry.npmjs.org/echarts/-/echarts-6.1.0.tgz",
       "integrity": "sha512-q0yaFPggC9FUdsWH4blavRWFmxdrIodbkoKNAjJudAI6CA9gNPxHtV2RcZNEepZVlk4yvBYkOkbk6HIVpIyHZA==",
-      "dev": true,
       "license": "Apache-2.0",
       "dependencies": {
         "tslib": "2.3.0",
@@ -5516,7 +5517,6 @@
       "version": "2.3.0",
       "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.3.0.tgz",
       "integrity": "sha512-N82ooyxVNm6h1riLCoyS9e3fuJ3AMG2zIZs2Gd1ATcSFjSA23Q0fzjjZeh0jbJvWVDZ0cJT8yaNNaaXHzueNjg==",
-      "dev": true,
       "license": "0BSD"
     },
     "node_modules/ejs": {
@@ -9558,7 +9558,6 @@
       "version": "6.1.0",
       "resolved": "https://registry.npmjs.org/zrender/-/zrender-6.1.0.tgz",
       "integrity": "sha512-oEGMDB6pOP2S6OwRR4PdVv610zrjnA3Bh+JnSG12fYJlBKjtNAoEb5fSUoCOOINlH96I2fU38/A2UpRKs67xYQ==",
-      "dev": true,
       "license": "BSD-3-Clause",
       "dependencies": {
         "tslib": "2.3.0"
@@ -9568,7 +9567,6 @@
       "version": "2.3.0",
       "resolved": "https://registry.npmjs.org/tslib/-/tslib-2.3.0.tgz",
       "integrity": "sha512-N82ooyxVNm6h1riLCoyS9e3fuJ3AMG2zIZs2Gd1ATcSFjSA23Q0fzjjZeh0jbJvWVDZ0cJT8yaNNaaXHzueNjg==",
-      "dev": true,
       "license": "0BSD"
     },
     "packages/application": {
@@ -9612,6 +9610,22 @@
         "markdown-it": "^14.3.0"
       }
     },
+    "packages/preview-engine": {
+      "name": "@md-to-pdf/preview-engine",
+      "version": "0.1.0",
+      "dependencies": {
+        "@md-to-pdf/core": "0.1.0",
+        "@md-to-pdf/markdown-echarts": "0.1.0",
+        "@mermaid-js/layout-elk": "0.2.2",
+        "echarts": "6.1.0",
+        "mermaid": "11.16.0",
+        "pagedjs": "^0.4.3"
+      },
+      "devDependencies": {
+        "happy-dom": "^20.11.1",
+        "vitest": "^4.1.10"
+      }
+    },
     "packages/renderer": {
       "name": "@md-to-pdf/renderer",
       "version": "0.1.0",