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/normalizer.ts

@@ -463,11 +463,21 @@ function normalizeComputedSlot(
       };
     }
   }
-  if (widthSlots.has(context.slot) && context.documentWidthPx) {
+  const containingBlockWidthPt = computed.containingBlockWidth
+    ? parseCssLengthToPt(computed.containingBlockWidth)
+    : undefined;
+  const relativeWidthPx =
+    containingBlockWidthPt !== undefined
+      ? containingBlockWidthPt / 0.75
+      : context.documentWidthPx;
+  if (
+    (widthSlots.has(context.slot) || context.kind === "structure") &&
+    relativeWidthPx
+  ) {
     const widthPt = parseCssLengthToPt(computed.width);
     const widthPx = widthPt === undefined ? undefined : widthPt / 0.75;
     if (widthPx !== undefined) {
-      const percent = (widthPx / context.documentWidthPx) * 100;
+      const percent = (widthPx / relativeWidthPx) * 100;
       style.widthPercent = Math.round(
         Math.max(0, Math.min(100, percent))
       );
@@ -482,6 +492,27 @@ function normalizeComputedSlot(
       }
     }
   }
+  if (context.kind === "structure" && context.documentWidthPx) {
+    const percentage = /^([+-]?(?:\d+\.?\d*|\.\d+))%$/u.exec(
+      computed.minWidth
+    );
+    const minimumWidthPercent = percentage
+      ? Number.parseFloat(percentage[1]!)
+      : (() => {
+          const minimumWidthPt = parseCssLengthToPt(computed.minWidth);
+          return minimumWidthPt === undefined
+            ? undefined
+            : ((minimumWidthPt / 0.75) / context.documentWidthPx) * 100;
+        })();
+    if (
+      minimumWidthPercent !== undefined &&
+      minimumWidthPercent > 0
+    ) {
+      style.minimumWidthPercent = roundDocxValue(
+        Math.min(100, minimumWidthPercent)
+      );
+    }
+  }
   const minimumHeightPt = length(
     context,
     "min-height",
@@ -491,6 +522,15 @@ function normalizeComputedSlot(
   if (minimumHeightPt !== undefined && minimumHeightPt > 0) {
     style.minimumHeightPt = minimumHeightPt;
   }
+  const contentPaddingLeftPt = computed.contentPaddingLeft
+    ? length(context, "content-padding-left", computed.contentPaddingLeft, {
+        allowAuto: true,
+        nonNegative: true
+      })
+    : undefined;
+  if (contentPaddingLeftPt !== undefined && contentPaddingLeftPt > 0) {
+    style.contentPaddingLeftPt = contentPaddingLeftPt;
+  }
   if (computed.display === "none") {
     style.hidden = true;
   }
@@ -512,6 +552,35 @@ function normalizeComputedSlot(
     if (resolved) {
       style.verticalAlignment = resolved;
     }
+    const childAlignment = {
+      "flex-start": "left",
+      start: "left",
+      center: "center",
+      "flex-end": "right",
+      end: "right",
+      stretch: "stretch"
+    } as const;
+    const resolvedChildAlignment =
+      childAlignment[
+        computed.alignItems as keyof typeof childAlignment
+      ];
+    if (resolvedChildAlignment) {
+      style.childAlignment = resolvedChildAlignment;
+    }
+  }
+  const selfAlignment = {
+    "flex-start": "left",
+    start: "left",
+    center: "center",
+    "flex-end": "right",
+    end: "right",
+    stretch: "stretch"
+  } as const;
+  const resolvedSelfAlignment = computed.alignSelf
+    ? selfAlignment[computed.alignSelf as keyof typeof selfAlignment]
+    : undefined;
+  if (resolvedSelfAlignment) {
+    style.selfAlignment = resolvedSelfAlignment;
   }
   if (computed.display === "flex" || computed.display === "grid") {
     diagnostic(context, {