feat: 插件适配页面与系统完善（v0.1.0）

- 修复 /categories、/tags 因变量为 List 误用 .items 导致的 500
- 新增 layout.html 布局契约，消除插件页面 fallback 警告
- 适配 plugin-moments / plugin-photos / plugin-links（含友链申请表单与 RSS 订阅页）
- 适配 halo-weread-plugin（书架页）、留言板单页模板
- 适配 plugin-extra-api 的代码高亮与暗色样式
- 修复暗黑模式评论区不可见（补充 color-scheme 与兜底样式）
- 更新元数据：作者暖心向阳335、版本 0.1.0、requires >=2.26.0

i18n/default.properties

@@ -0,0 +1,35 @@
+nav.home=Home
+nav.archives=Archives
+nav.categories=Categories
+nav.tags=Tags
+search.title=Search
+theme.toggle=Toggle theme
+mobile.menu=Menu
+back.to.top=Back to top
+post.views={0} views
+post.continue=Continue reading
+pagination.previous=Previous
+pagination.next=Next
+pagination.page=Page {0} of {1}
+list.empty=Nothing found here.
+home.featured=Featured
+archive.title=Archives
+archive.stats.posts=Posts
+archive.stats.categories=Categories
+archive.stats.tags=Tags
+archive.stats.years=Years
+categories.title=Categories
+tags.title=Tags
+tag.count=posts
+category.title=Category
+tag.title=Tag
+author.title=Author
+search.keyword=Keyword
+error.404.title=Page not found
+error.404.message=Sorry, the page you visited does not exist or has been deleted.
+error.back.home=Back to home
+error.back.prev=Go back
+footer.theme=Theme by {0}
+about.social.github=GitHub
+about.social.twitter=Twitter
+about.social.email=Email