feat: 增加 ECharts 渲染与预览交互增强

- 新增可复用的 markdown-echarts 工作区，支持安全的 YAML 围栏、默认值、语义校验、错误占位和 SVG 渲染
- 将 ECharts 接入统一 Markdown、快速预览、精确预览与 PDF 链路，并复用 Mermaid 的不可跨页和超高图单页适配策略
- 默认示例加入 ECharts，增加源文本折叠、顶部文档状态、页码输入跳转与滚动同步
- 快速预览改用外层容器滚动，使滚动条与精确预览统一贴在预览区域右侧，并兼容显示缩放
- 完善 Docker 工作区复制、可配置 Compose 镜像、测试覆盖和进度文档

packages/renderer/src/render-markdown.ts

@@ -7,6 +7,10 @@ import type {
   RenderedMarkdownDocument,
   ThemeFeature
 } from "@md-to-pdf/core";
+import {
+  markdownItECharts,
+  type MarkdownItEChartsErrorContext
+} from "@md-to-pdf/markdown-echarts";
 import matter from "gray-matter";
 import hljs from "highlight.js";
 import MarkdownIt from "markdown-it";
@@ -110,6 +114,17 @@ markdown.renderer.rules.fence = (
   return renderFallbackFence(tokens, index, renderer);
 };
 
+markdown.use(markdownItECharts, {
+  onError(error, context: MarkdownItEChartsErrorContext) {
+    const environment = context.environment as
+      | { warnings?: string[] }
+      | undefined;
+    environment?.warnings?.push(
+      `ECharts 图表配置无效：${error.message}`
+    );
+  }
+});
+
 const safeHtmlOptions: sanitizeHtml.IOptions = {
   allowedTags: [
     ...sanitizeHtml.defaults.allowedTags,
@@ -130,10 +145,16 @@ const safeHtmlOptions: sanitizeHtml.IOptions = {
     "*": ["class", "id", "title", "aria-*", "role"],
     a: ["href", "name", "target", "rel"],
     div: ["class", "data-mermaid-pending"],
+    figure: [
+      "class",
+      "data-echarts-pending",
+      "data-echarts-protocol"
+    ],
     img: ["src", "alt", "title", "width", "height"],
     input: ["type", "checked", "disabled", "class"],
     li: ["class", "value"],
     ol: ["class", "start"],
+    pre: ["class", "hidden"],
     span: ["class", "style"],
     td: ["colspan", "rowspan", "style"],
     th: ["colspan", "rowspan", "scope", "style"]
@@ -262,7 +283,8 @@ function detectFeatures(html: string): ThemeFeature[] {
     ["task-list", /\bmd-task-list-item\b/u],
     ["footnote", /\bfootnote/u],
     ["katex", /\bkatex\b/u],
-    ["mermaid", /\bmermaid\b/u]
+    ["mermaid", /\bmermaid\b/u],
+    ["echarts", /\bmd-echarts\b/u]
   ];
 
   return featureChecks