feat(v1.2.7): 全面校准文档并精简三个可选 API 配置项文案

- 文档对齐 1.2.7：feed/RSS 聚合改由官方链接管理插件订阅承担、Halo 要求统一 >=2.27.0、补齐设置分组文档、清理与代码不符的描述，并修复正文引用块留白
- 三个可选 API 设置项 help 只保留功能说明，隐私披露统一由 README「外部资源与隐私」与文档站承载；字段恢复按开关条件显示，修正配置块缩进
- audit:external 改为防回潮检查：字段存在、help 不得出现披露文案、README 必须保留隐私披露章节

docs/.vitepress/config.mts

@@ -35,7 +35,9 @@ export default defineConfig({
           { text: '瞬间', link: '/config/moments' },
           { text: '图库', link: '/config/photos' },
           { text: '友情链接', link: '/config/links' },
-          { text: '朋友圈', link: '/config/friends' },
+          { text: '订阅', link: '/config/subscriptions' },
+          { text: '欢迎弹窗', link: '/config/welcome-popup' },
+          { text: '微信读书', link: '/config/weread' },
           { text: '记得', link: '/config/important-dates' },
           { text: '留言板', link: '/config/messageboard' },
           { text: '评论', link: '/config/comment' },
@@ -53,7 +55,7 @@ export default defineConfig({
           { text: '瞬间', link: '/pages/moments' },
           { text: '图库', link: '/pages/photos' },
           { text: '友情链接', link: '/pages/links' },
-          { text: '朋友圈', link: '/pages/friends' },
+          { text: '订阅', link: '/pages/subscriptions' },
           { text: '记得', link: '/pages/important-dates' },
           { text: '自定义页面', link: '/pages/custom-page' },
           { text: '扩展页面', link: '/pages/extended' },