feat: 完善 Mermaid 配置与预览缩放

packages/renderer/tests/render-markdown.test.ts

@@ -95,21 +95,34 @@ flowchart LR
 ---
 title: Frontmatter 示例
 config:
+  layout: elk
   theme: forest
   look: handDrawn
+  fontFamily: Microsoft YaHei
+  themeVariables:
+    primaryColor: "#dbeafe"
   flowchart:
     curve: basis
 ---
 flowchart LR
+  classDef important fill:#fee2e2,stroke:#dc2626
   A[开始] --> B[结束]
+  style A fill:#dcfce7,stroke:#16a34a
+  class B important
 \`\`\`
 `);
 
     expect(result.bodyHtml).toContain("title: Frontmatter 示例");
+    expect(result.bodyHtml).toContain("layout: elk");
     expect(result.bodyHtml).toContain("theme: forest");
     expect(result.bodyHtml).toContain("look: handDrawn");
+    expect(result.bodyHtml).toContain("fontFamily: Microsoft YaHei");
+    expect(result.bodyHtml).toContain("primaryColor:");
     expect(result.bodyHtml).toContain("curve: basis");
     expect(result.bodyHtml).toContain("flowchart LR");
+    expect(result.bodyHtml).toContain("classDef important");
+    expect(result.bodyHtml).toContain("style A fill:");
+    expect(result.bodyHtml).toContain("class B important");
   });
 
   it("阻止原始 HTML 和危险链接形成可执行内容", () => {