feat(cms): 文章页标题下说明后台可编辑 + 文章数 {n} 占位符随数量变化

后台「页面文案」新增「文章页说明」（中/英 markdown，与瞬间/书架同构的
压平结构）；{n} 在构建期替换为当前可见文章数。顺修默认文案错字
（月分分组→按月分组），en 文章页补齐标题与说明行（此前只有裸列表）。

验证: pnpm astro build exit 0；dist 断言「共 10 篇」动态计数与 en 侧文案；config-check 通过；E2E 61/61

Spec: none (页面文案体系的小增量，随 5l/5m 后续直落)

Co-authored-by: GLM-5.3

content/site/pages.yaml

@@ -9,3 +9,7 @@ moments:
 books:
   note_zh: 点一行展开封面与简介 · 置顶的书默认展开
   note_en: 'Tap a row for the cover and blurb · pinned books start open'
+
+archives:
+  note_zh: 按年份折叠 · 按月分组 · 共 {n} 篇
+  note_en: 'Folded by year · grouped by month · {n} posts in total'

public/admin/config.yml

@@ -170,6 +170,13 @@ collections:
             fields:
               - { label: 中文, name: note_zh, widget: markdown, required: false, hint: '一行小字；排版（字体/颜色）选中文字 → Insert ▸ 排版' }
               - { label: English, name: note_en, widget: markdown, required: false }
+          - label: 文章页说明
+            name: archives
+            widget: object
+            required: false
+            fields:
+              - { label: 中文, name: note_zh, widget: markdown, required: false, hint: '一行小字；{n} 会替换为当前可见文章数（构建期）；排版用 Insert ▸ 排版' }
+              - { label: English, name: note_en, widget: markdown, required: false }
       - name: home
         label: 主页设置
         file: content/site/home.yaml

src/content.config.ts

@@ -246,6 +246,7 @@ export const collections = {
     schema: z.object({
       moments: pageNoteSchema.optional(),
       books: pageNoteSchema.optional(),
+      archives: pageNoteSchema.optional(),
     }),
   }),
   siteTheme: defineCollection({

src/lib/site-content.ts

@@ -181,6 +181,10 @@ const PAGE_NOTE_DEFAULTS = {
     zh: '点一行展开封面与简介 · 置顶的书默认展开',
     en: 'Tap a row for the cover and blurb · pinned books start open',
   },
+  archives: {
+    zh: '按年份折叠 · 按月分组 · 共 {n} 篇',
+    en: 'Folded by year · grouped by month · {n} posts in total',
+  },
 } as const;
 
 /**
@@ -191,13 +195,16 @@ const PAGE_NOTE_DEFAULTS = {
  * 「可选对象嵌可选对象不渲染子编辑器」的缺陷结构（#446/#654）。
  */
 export async function pageNote(
-  page: 'moments' | 'books',
+  page: 'moments' | 'books' | 'archives',
   locale: Locale,
+  /** 占位符替换（在 markdown 渲染前做）：文章页用 {n}=可见文章数 */
+  vars?: Record<string, string | number>,
 ): Promise<PageNote> {
   const entry = await getEntry('sitePages', 'pages');
   const data = entry?.data?.[page];
   const fallback = PAGE_NOTE_DEFAULTS[page];
-  const text = (locale === 'en' ? data?.note_en : data?.note_zh) || fallback[locale];
+  let text = (locale === 'en' ? data?.note_en : data?.note_zh) || fallback[locale];
+  if (vars) for (const [k, v] of Object.entries(vars)) text = text.replaceAll(`{${k}}`, String(v));
   const html = await renderRich(text, { inline: true });
   return { html, className: 'page-note' };
 }

src/pages/archives/index.astro

@@ -5,16 +5,19 @@ import { isVisiblePost } from '../../lib/post-visibility';
 import BaseLayout from '../../layouts/BaseLayout.astro';
 import PostList from '../../components/PostList.astro';
 import { sortPosts } from '../../lib/post-order';
+import { pageNote } from '../../lib/site-content';
 
 // 置顶优先 → 时间倒序（sortPosts 契约见 src/lib/post-order.ts）
 const posts = sortPosts(
   await getCollection('posts', ({ data }) => isVisiblePost(data)),
 );
+// 标题下说明：后台「页面文案 → 文章页说明」可改；{n} 占位符=可见文章数（构建期替换）
+const note = await pageNote('archives', 'zh', { n: posts.length });
 ---
 
 <BaseLayout title="文章 · wait4x">
   <h1 class="page-title">文章</h1>
-  <p class="page-note">按年份折叠 · 月分分组 · 共 {posts.length} 篇</p>
+  <p class="page-note" set:html={note.html} />
   <PostList {posts} fold />
 </BaseLayout>
 

src/pages/en/archives/index.astro

@@ -5,6 +5,7 @@ import { isVisiblePost } from '../../../lib/post-visibility';
 import BaseLayout from '../../../layouts/BaseLayout.astro';
 import PostList from '../../../components/PostList.astro';
 import { sortPosts } from '../../../lib/post-order';
+import { pageNote } from '../../../lib/site-content';
 
 const posts = sortPosts(
   await getCollection('posts', ({ data }) => isVisiblePost(data)),
@@ -12,8 +13,26 @@ const posts = sortPosts(
 const enTitle = Object.fromEntries(
   (await getCollection('postsEn')).map((e) => [e.id, e.data.title]),
 );
+const note = await pageNote('archives', 'en', { n: posts.length });
 ---
 
 <BaseLayout title="Posts · wait4x" description="All posts">
+  <h1 class="page-title">Posts</h1>
+  <p class="page-note" set:html={note.html} />
   <PostList {posts} locale="en" titleOverrides={enTitle} fold />
 </BaseLayout>
+
+<style>
+  .page-title {
+    font-size: var(--text-h1);
+    line-height: var(--leading-heading);
+    color: var(--ink-1);
+    margin-top: var(--space-5);
+    text-wrap: balance;
+  }
+  .page-note {
+    font-size: 13px;
+    color: var(--ink-4);
+    margin-block: var(--space-1) var(--space-4);
+  }
+</style>