feat(pages): /books 书架与 /opensource 开源页——导航第四项（T2/T5）

- BooksPage：色脊排版卡（mood 竖脊+文楷书名+作者+三行截断策展语）
  × 年份分组规整网格；zh/en 双路由；阅读轨标题旁「书架 →」入口
- /opensource：全量仓墙（ProjectWall 加 limit prop，首页精选 6 不变）
  + 热力图 + 本站开源叙事段；导航第四项「开源」（i18n nav_opensource）
- 五书 frontmatter 策展字段（含泥潭=刘楚昕）

验证: build 28 页 exit 0；books/opensource zh/en 五路由产物断言过；
      五书卡与作者 grep 在案；E2E 30/30 PASS

Spec: 2026-10-25_add-terminal-books-admin

Co-authored-by: GLM-5.3

src/pages/books.astro

@@ -0,0 +1,4 @@
+---
+import BooksPage from '../components/pages/BooksPage.astro';
+---
+<BooksPage locale="zh" />

src/pages/en/books.astro

@@ -0,0 +1,4 @@
+---
+import BooksPage from '../../components/pages/BooksPage.astro';
+---
+<BooksPage locale="en" />

src/pages/en/opensource.astro

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+---
+import ProjectWall from '../../components/geek/ProjectWall.astro';
+import Heatmap from '../../components/geek/Heatmap.astro';
+import BaseLayout from '../../layouts/BaseLayout.astro';
+import { t } from '../../i18n/ui';
+---
+<BaseLayout title="Open Source · wait4x" description="My open-source activity: repos, contributions, and this site's source">
+  <h1 class="page-title">Open Source</h1>
+  <p class="blurb">This site is itself open source: <a class="link" href="https://git.wait4x.online/wait4x/blog">git.wait4x.online/wait4x/blog</a> — the Astro SSG, dual-writing workflow, and the full build &amp; deploy pipeline live in the repo. Below are all my public repositories on self-hosted gitea and GitHub, plus contributions from the past year.</p>
+  <Heatmap labels={{
+    title: t('heatmap_title', 'en'), summary: t('heatmap_summary', 'en'),
+    less: t('heatmap_less', 'en'), more: t('heatmap_more', 'en'), note: t('heatmap_note', 'en'),
+  }} />
+  <ProjectWall limit={99} />
+</BaseLayout>
+
+<style>
+  .page-title { font-size: var(--text-h1); color: var(--ink-1); }
+  .blurb { margin-top: var(--space-3); margin-bottom: var(--space-5); font-size: 15px; color: var(--ink-2); line-height: 1.7; max-width: 640px; }
+</style>

src/pages/opensource.astro

@@ -0,0 +1,21 @@
+---
+import ProjectWall from '../components/geek/ProjectWall.astro';
+import Heatmap from '../components/geek/Heatmap.astro';
+import BaseLayout from '../layouts/BaseLayout.astro';
+import { t } from '../i18n/ui';
+---
+<BaseLayout title="开源 · wait4x" description="我的开源活动：仓库、贡献与本站源码">
+  <h1 class="page-title">开源<span class="count mono">Open Source</span></h1>
+  <p class="blurb">本站本身即开源：<a class="link" href="https://git.wait4x.online/wait4x/blog">git.wait4x.online/wait4x/blog</a> —— Astro SSG、双写作流、构建发布全链皆在仓中。以下是我在自托管 gitea 与 GitHub 上的全部公开仓库，以及最近一年的贡献活动。</p>
+  <Heatmap labels={{
+    title: t('heatmap_title', 'zh'), summary: t('heatmap_summary', 'zh'),
+    less: t('heatmap_less', 'zh'), more: t('heatmap_more', 'zh'), note: t('heatmap_note', 'zh'),
+  }} />
+  <ProjectWall limit={99} />
+</BaseLayout>
+
+<style>
+  .page-title { font-size: var(--text-h1); color: var(--ink-1); display: flex; align-items: baseline; gap: var(--space-3); }
+  .count { font-size: 13px; color: var(--ink-4); }
+  .blurb { margin-top: var(--space-3); margin-bottom: var(--space-5); font-size: 15px; color: var(--ink-2); line-height: 1.7; max-width: 640px; }
+</style>