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/docx-theme-engine/src/runtime.ts

@@ -75,6 +75,7 @@ const computedProperties = [
   "borderLeft",
   "width",
   "maxWidth",
+  "minWidth",
   "minHeight",
   "height",
   "breakBefore",
@@ -83,6 +84,7 @@ const computedProperties = [
   "display",
   "flexDirection",
   "alignItems",
+  "alignSelf",
   "justifyContent",
   "outline",
   "outlineOffset"
@@ -104,6 +106,23 @@ body {
   margin: 0;
   padding: 0;
 }
+
+#write pre.md-fences > code,
+#write .md-code-pagination-chunk > code {
+  display: block;
+  min-width: 0;
+  max-width: 100%;
+  padding: 0;
+  padding-left: 8px;
+  border: 0;
+  border-radius: 0;
+  background: transparent;
+  box-shadow: none;
+  font-family: inherit;
+  font-size: inherit;
+  font-weight: inherit;
+  line-height: inherit;
+}
 `;
 
 export function createDocxThemeStyleCaptureScript(
@@ -190,6 +209,29 @@ export function createDocxThemeStyleCaptureScript(
         for (const property of payload.properties) {
           computed[property] = style[property];
         }
+        const contentElement = element.firstElementChild;
+        if (contentElement) {
+          computed.contentPaddingLeft =
+            probeWindow.getComputedStyle(contentElement).paddingLeft;
+        }
+        const containingBlock = element.parentElement;
+        if (containingBlock) {
+          const containingStyle = probeWindow.getComputedStyle(
+            containingBlock
+          );
+          const containingRect = containingBlock.getBoundingClientRect();
+          const horizontalInsets = [
+            containingStyle.borderLeftWidth,
+            containingStyle.borderRightWidth,
+            containingStyle.paddingLeft,
+            containingStyle.paddingRight
+          ].reduce(
+            (total, value) => total + (Number.parseFloat(value) || 0),
+            0
+          );
+          computed.containingBlockWidth =
+            Math.max(0, containingRect.width - horizontalInsets) + "px";
+        }
         return {
           slot: definition.name,
           matched: true,