chore: 升级 Astro 5.16.5 → 7.3.3

依赖
- astro 5 → 7.3.3，@astrojs/{mdx,react,rss,sitemap,check}、astro-expressive-code
  与 @swup/astro 同步升到最新
- 新增 @astrojs/markdown-remark（Astro 7 默认改用 Sätteri 处理器，
  本项目依赖大量 remark/rehype 插件，故显式固定回 unified 管线）

内容集合迁移到 Content Layer API（Astro 6 已移除旧 API）
- src/content/config.ts → src/content.config.ts，三个集合改用 glob() loader
- z 改从 astro/zod 导入
- 所有 entry.slug → entry.id；entry.render() → render(entry)

Astro 7 兼容
- 修复 bookshelf-content.astro 里多行 {/* */} 注释导致的 Rust 编译器
  "Unterminated regular expression"
- 删除该文件里一处多余的 </div>（旧 Go 编译器会静默纠正，新编译器不会）
- global.css: @import "tailwindcss" → "tailwindcss/index.css"
  （Vite 8 不再解析裸包名的 style 条件）
- astro.config.mjs 显式设置 compressHTML: true，保持 v6 的空白处理行为

验证：构建 41 页通过；与线上（Astro 5 构建）对比 39 个 URL 无一丢失，
仅新增新文章 DIY-computer 的 2 个 URL；逐页渲染文本与线上一致；
pnpm build 与 dev server 均正常。

astro.config.mjs

@@ -21,6 +21,7 @@ import { remarkExcerpt } from "./src/plugins/remark-excerpt.js"
 import { remarkReadingTime } from "./src/plugins/remark-reading-time.mjs"
 import { pluginLanguageBadge } from "./src/plugins/expressive-code/language-badge"
 import { pluginCustomCopyButton } from "./src/plugins/expressive-code/custom-copy-button"
+import { unified } from "@astrojs/markdown-remark"
 import { site } from "./src/data/site"
 
 const createAdmonitionComponent = (type) => (properties = {}, children = []) => {
@@ -85,57 +86,60 @@ export default defineConfig({
     sitemap(),
     mdx(),
   ],
+  compressHTML: true,
   markdown: {
-    remarkPlugins: [
-      remarkMath,
-      remarkReadingTime,
-      remarkExcerpt,
-      remarkShiftHeadings,
-      remarkGithubAdmonitionsToDirectives,
-      remarkDirective,
-      remarkSectionize,
-      parseDirectiveNode,
-    ],
-    rehypePlugins: [
-      rehypeKatex,
-      rehypeSlug,
-      [
-        rehypeComponents,
-        {
-          components: {
-            github: GithubCardComponent,
-            note: createAdmonitionComponent("note"),
-            tip: createAdmonitionComponent("tip"),
-            important: createAdmonitionComponent("important"),
-            caution: createAdmonitionComponent("caution"),
-            warning: createAdmonitionComponent("warning"),
-          },
-        },
+    processor: unified({
+      remarkPlugins: [
+        remarkMath,
+        remarkReadingTime,
+        remarkExcerpt,
+        remarkShiftHeadings,
+        remarkGithubAdmonitionsToDirectives,
+        remarkDirective,
+        remarkSectionize,
+        parseDirectiveNode,
       ],
-      [
-        rehypeAutolinkHeadings,
-        {
-          behavior: "append",
-          properties: {
-            className: ["anchor"],
-          },
-          content: {
-            type: "element",
-            tagName: "span",
-            properties: {
-              className: ["anchor-icon"],
-              "data-pagefind-ignore": true,
+      rehypePlugins: [
+        rehypeKatex,
+        rehypeSlug,
+        [
+          rehypeComponents,
+          {
+            components: {
+              github: GithubCardComponent,
+              note: createAdmonitionComponent("note"),
+              tip: createAdmonitionComponent("tip"),
+              important: createAdmonitionComponent("important"),
+              caution: createAdmonitionComponent("caution"),
+              warning: createAdmonitionComponent("warning"),
             },
-            children: [
-              {
-                type: "text",
-                value: "#",
-              },
-            ],
           },
-        },
+        ],
+        [
+          rehypeAutolinkHeadings,
+          {
+            behavior: "append",
+            properties: {
+              className: ["anchor"],
+            },
+            content: {
+              type: "element",
+              tagName: "span",
+              properties: {
+                className: ["anchor-icon"],
+                "data-pagefind-ignore": true,
+              },
+              children: [
+                {
+                  type: "text",
+                  value: "#",
+                },
+              ],
+            },
+          },
+        ],
       ],
-    ],
+    }),
   },
   vite: {
     server: {