refactor(admin): 重构设置页面并添加全局 toast 提示

- 将通知邮箱设置卡片移至评论配置下方
- 添加全局 toast 提示组件替代原有表单消息
- 简化错误消息显示逻辑
- 更新数据库查询语句以匹配新增设置项

cwd-comments-api/src/index.ts

@@ -32,7 +32,7 @@ async function loadCommentSettings(env: Bindings) {
 		COMMENT_ADMIN_ENABLED_KEY
 	];
 	const { results } = await env.CWD_DB.prepare(
-		'SELECT key, value FROM Settings WHERE key IN (?, ?, ?)'
+		'SELECT key, value FROM Settings WHERE key IN (?, ?, ?, ?)'
 	)
 		.bind(...keys)
 		.all<{ key: string; value: string }>();