feat: 完成 DOCX R4 元素级视觉门禁

建立 Chromium、Word 与 WPS 的可编辑内容、段落几何、页眉页脚、封面、媒体和逐页视觉比较链路。

支持封面独立分节、正文页码重启、主题页边距与横向纸张，并将自然分页差异降为诊断项。

修正代码块内边距和折叠表格单元格边框映射，14 套主题生产矩阵与六组布局视觉矩阵通过。

packages/application/tests/bundled-themes.test.ts

@@ -199,6 +199,40 @@ describe("内置主题清单", () => {
     }
   });
 
+  it("可研封面使用跨 Chromium 与 Word 一致的原生字体面", async () => {
+    const [css, manifestSource] = await Promise.all([
+      readFile(
+        new URL(
+          "../../../themes/formal-feasibility/theme.css",
+          import.meta.url
+        ),
+        "utf8"
+      ),
+      readFile(
+        new URL(
+          "../../../themes/formal-feasibility/theme.json",
+          import.meta.url
+        ),
+        "utf8"
+      )
+    ]);
+    const manifest = JSON.parse(manifestSource) as {
+      docxFonts?: {
+        faces?: Array<{ family: string; weight?: number }>;
+      };
+    };
+
+    expect(css).toContain('"FandolSong", "Noto Serif CJK SC"');
+    expect(css).toContain('"FandolHei", "Noto Sans CJK SC"');
+    expect(manifest.docxFonts?.faces).toEqual(
+      expect.arrayContaining([
+        expect.objectContaining({ family: "FandolSong", weight: 400 }),
+        expect.objectContaining({ family: "FandolSong", weight: 700 }),
+        expect.objectContaining({ family: "FandolHei", weight: 400 })
+      ])
+    );
+  });
+
   it("技术暗标主题隐藏结构化身份字段", async () => {
     const css = await readFile(
       new URL(