feat(md-print): add timestamp footer option

src/cli/validate/known.ts

@@ -77,16 +77,18 @@ export const KNOWN_ELEMENTS: readonly ElementSpec[] = [
       "font",
       "title",
       "pageNumbers",
+      "timestamp",
       "cutMarks",
     ],
     summary:
       "Paginates a markdown document into A4 landscape sheets for printing.",
     details:
-      "Each sheet holds two A5 pages side by side, and each A5 page flows the markdown into `columns` columns. `margin`, `gap`, and `font` are in millimetres (the body font defaults to 3mm). `pageNumbers` adds an `n / total` footer in the outer corner and `cutMarks` draws the centre cut line. The preview modal exports through the browser's print dialog (choose A4 landscape, no margins, 100% scale).",
+      "Each sheet holds two A5 pages side by side, and each A5 page flows the markdown into `columns` columns. `margin`, `gap`, and `font` are in millimetres (the body font defaults to 3mm). `pageNumbers` adds an `n / total` footer in the outer corner, `timestamp` appends the export time to that footer, and `cutMarks` draws the centre cut line. The preview modal exports through the browser's print dialog (choose A4 landscape, no margins, 100% scale).",
     refKind: "md",
     examples: [
       ':md-print[./rules.md]{columns="2" margin="10" gap="5" font="3"}',
-      "```yaml role=tag\ntag: md-print\nbody: ./rules.md\ncolumns: 2\nmargin: 10\ngap: 5\nfont: 3\ntitle: 规则书\n```",
+      ':md-print[./rules.md]{timestamp=true}',
+      "```yaml role=tag\ntag: md-print\nbody: ./rules.md\ncolumns: 2\nmargin: 10\ngap: 5\nfont: 3\ntitle: 规则书\ntimestamp: true\n```",
     ],
   },
   {

src/components/md-print/PrintPreview.tsx

@@ -28,6 +28,11 @@ import {
 } from "./paginate";
 import { exportPrintPDF } from "./print-export";
 
+function formatTimestamp(date: Date): string {
+  const pad = (n: number) => String(n).padStart(2, "0");
+  return `${date.getFullYear()}-${pad(date.getMonth() + 1)}-${pad(date.getDate())} ${pad(date.getHours())}:${pad(date.getMinutes())}`;
+}
+
 export interface PrintPreviewProps {
   src: string;
   section?: string;
@@ -69,6 +74,23 @@ export function PrintPreview(props: PrintPreviewProps) {
     articlePath: props.articlePath,
   });
 
+  const applyFooter = (pageList: HTMLElement[], timestamp: string) => {
+    pageList.forEach((page, index) => {
+      const footer = page.querySelector(".md-print-footer");
+      if (!footer) return;
+      const pageLabel = props.config.pageNumbers
+        ? `${index + 1} / ${pageList.length}`
+        : "";
+      footer.textContent = [pageLabel, timestamp].filter(Boolean).join(" · ");
+      // Left A5 gets the left corner, right A5 gets the right corner.
+      footer.classList.add(
+        index % 2 === 0
+          ? "md-print-footer--left"
+          : "md-print-footer--right",
+      );
+    });
+  };
+
   const runPagination = async () => {
     const md = content();
     const source = sourceEl();
@@ -88,18 +110,10 @@ export function PrintPreview(props: PrintPreviewProps) {
       await waitForStableSize(source, 300, 4000);
 
       const result = paginate(source, options(), mount);
-      result.pages.forEach((page, index) => {
-        const footer = page.querySelector(".md-print-footer");
-        if (footer) {
-          footer.textContent = `${index + 1} / ${result.pages.length}`;
-          // Left A5 gets the left corner, right A5 gets the right corner.
-          footer.classList.add(
-            index % 2 === 0
-              ? "md-print-footer--left"
-              : "md-print-footer--right",
-          );
-        }
-      });
+      applyFooter(
+        result.pages,
+        props.config.timestamp ? formatTimestamp(new Date()) : "",
+      );
       setPages(result.pages);
       setWarnings(result.warnings);
     } catch (e) {
@@ -164,6 +178,10 @@ export function PrintPreview(props: PrintPreviewProps) {
 
   const handleExport = async () => {
     try {
+      // Refresh the timestamp so the exported file records the export time.
+      if (props.config.timestamp) {
+        applyFooter(pages(), formatTimestamp(new Date()));
+      }
       await exportPrintPDF(pages(), props.config, title(), props.articlePath);
     } catch (e) {
       setError(e instanceof Error ? e.message : String(e));

src/components/md-print/config.test.ts

@@ -12,6 +12,7 @@ describe("normalizePrintConfig", () => {
       gap: "-5",
       font: "20",
       pageNumbers: "false",
+      timestamp: "true",
       cutMarks: "no",
     });
 
@@ -20,6 +21,7 @@ describe("normalizePrintConfig", () => {
     expect(config.gap).toBe(0);
     expect(config.font).toBe(6);
     expect(config.pageNumbers).toBe(false);
+    expect(config.timestamp).toBe(true);
     expect(config.cutMarks).toBe(false);
   });
 
@@ -41,6 +43,7 @@ describe("normalizePrintConfig", () => {
       font: 3,
       title: "规则书",
       pageNumbers: true,
+      timestamp: true,
       cutMarks: false,
     });
 
@@ -51,7 +54,13 @@ describe("normalizePrintConfig", () => {
       font: 3,
       title: "规则书",
       pageNumbers: true,
+      timestamp: true,
       cutMarks: false,
     });
   });
+
+  test("timestamp defaults to false", () => {
+    expect(normalizePrintConfig().timestamp).toBe(false);
+    expect(normalizePrintConfig({ timestamp: "false" }).timestamp).toBe(false);
+  });
 });

src/components/md-print/config.ts

@@ -7,6 +7,7 @@ export const PRINT_DEFAULTS: PrintConfig = {
   font: 3,
   title: "",
   pageNumbers: true,
+  timestamp: false,
   cutMarks: true,
 };
 
@@ -47,6 +48,7 @@ export function normalizePrintConfig(
     title:
       typeof input.title === "string" ? input.title : PRINT_DEFAULTS.title,
     pageNumbers: toBoolean(input.pageNumbers, PRINT_DEFAULTS.pageNumbers),
+    timestamp: toBoolean(input.timestamp, PRINT_DEFAULTS.timestamp),
     cutMarks: toBoolean(input.cutMarks, PRINT_DEFAULTS.cutMarks),
   };
 }

src/components/md-print/index.tsx

@@ -15,6 +15,7 @@ customElement<PrintProps>(
     font: "3",
     title: "",
     pageNumbers: "true",
+    timestamp: "false",
     cutMarks: "true",
   },
   (props, { element }) => {

src/components/md-print/paginate.test.ts

@@ -2,7 +2,42 @@
  * @jest-environment jsdom
  */
 
-import { splitTextElementAt } from "./paginate";
+import { PRINT_DEFAULTS } from "./config";
+import { createPageElement, splitTextElementAt } from "./paginate";
+
+describe("createPageElement", () => {
+  const base = { ...PRINT_DEFAULTS, articlePath: "rules.md" };
+
+  test("adds a footer when page numbers are enabled", () => {
+    const { page } = createPageElement({
+      ...base,
+      pageNumbers: true,
+      timestamp: false,
+    });
+
+    expect(page.querySelector(".md-print-footer")).not.toBeNull();
+  });
+
+  test("adds a footer when only the timestamp is enabled", () => {
+    const { page } = createPageElement({
+      ...base,
+      pageNumbers: false,
+      timestamp: true,
+    });
+
+    expect(page.querySelector(".md-print-footer")).not.toBeNull();
+  });
+
+  test("omits the footer when both are disabled", () => {
+    const { page } = createPageElement({
+      ...base,
+      pageNumbers: false,
+      timestamp: false,
+    });
+
+    expect(page.querySelector(".md-print-footer")).toBeNull();
+  });
+});
 
 describe("splitTextElementAt", () => {
   test("splits at a word boundary", () => {

src/components/md-print/paginate.ts

@@ -72,7 +72,7 @@ export function createPageElement(opts: PaginateOptions): {
   flow.style.width = "100%";
   page.appendChild(flow);
 
-  if (opts.pageNumbers) {
+  if (opts.pageNumbers || opts.timestamp) {
     const footer = document.createElement("div");
     footer.className = "md-print-footer";
     page.appendChild(footer);

src/components/md-print/types.ts

@@ -11,6 +11,8 @@ export interface PrintConfig {
   title: string;
   /** Show `n / total` in the page footer. */
   pageNumbers: boolean;
+  /** Append the export timestamp to the page footer. */
+  timestamp: boolean;
   /** Draw the centre cut line between the two A5 pages. */
   cutMarks: boolean;
 }
@@ -22,5 +24,6 @@ export interface PrintProps {
   font?: string | number;
   title?: string;
   pageNumbers?: string | boolean;
+  timestamp?: string | boolean;
   cutMarks?: string | boolean;
 }

src/doc-entries/md-print.md

@@ -20,6 +20,12 @@ title: 打印版式
 :md-print[./rules.md]{columns="2" margin="10" gap="5" font="3"}
 ```
 
+**在页脚显示导出时间：**
+
+```markdown
+:md-print[./rules.md]{timestamp=true}
+```
+
 **YAML 写法：**
 
 ```yaml
@@ -30,6 +36,7 @@ margin: 10
 gap: 5
 font: 3
 title: 规则书
+timestamp: true
 ```
 
 点击组件上的「打印预览 / 导出 PDF」按钮打开预览。预览中会显示分页后的 A4 横版页面，可以直接打印或另存为 PDF。
@@ -44,8 +51,11 @@ title: 规则书
 | `font` | number | `3` | 正文字号（毫米） |
 | `title` | string | — | 页眉标题 |
 | `pageNumbers` | boolean | `true` | 是否在页面外侧角落显示 `n / 总数` 页码 |
+| `timestamp` | boolean | `false` | 是否在页码旁边显示导出时间 |
 | `cutMarks` | boolean | `true` | 是否显示 A4 中缝裁切线 |
 
+页码位于页面外侧底角：左侧 A5 在左下角，右侧 A5 在右下角。开启 `timestamp` 后，页脚会显示类似 `3 / 12 · 2026-10-23 14:05` 的内容。
+
 ## 打印设置
 
 在浏览器打印对话框中：

src/styles.css

@@ -274,9 +274,12 @@ icon.big .icon-label-stroke {
     position: absolute;
     bottom: 3mm;
     left: 3mm;
+    max-width: calc(100% - 6mm);
     font-size: 8pt;
     color: #6b7280;
     white-space: nowrap;
+    overflow: hidden;
+    text-overflow: ellipsis;
 }
 
 .md-print-footer--left {