feat: document advanced redirect domains

Assisted-by: OpenAI Codex (GPT-5)

Author: taoky

src/css/about.scss

@@ -136,6 +136,16 @@
   }
 }
 
+.about-redirect-patterns {
+  code {
+    font-size: 0.92em;
+  }
+
+  p {
+    margin: 2px 0 10px;
+  }
+}
+
 .about-logo {
   display: block;
   width: 52px;

src/i18n/emoji.json

@@ -57,6 +57,10 @@
     "302_js_description": "Experimental redirects to a suitable mirror site.",
     "302_go": "302 Backend",
     "302_go_description": "Redirect to a participating site using network and health information.",
+    "302_go_preferences": "Add mirror labels to the domain to prefer or exclude sites.",
+    "302_go_prefer_one": "Prefer TUNA, with other sites as fallback candidates.",
+    "302_go_prefer_multiple": "Prefer USTC, then TUNA; the rightmost label has higher priority.",
+    "302_go_avoid": "Exclude TUNA completely.",
     "search": "Experimental Feature: Search Backend",
     "search_description": "Find a file path on a mirror site.",
     "monitor": "📈 Status",

src/i18n/en.json

@@ -59,6 +59,10 @@
     "302_go": "302 Backend",
     "302_go_more": "Check help for mirrors for usage",
     "302_go_description": "Use one mirror address and be redirected to a participating site based on network location and site status. See mirror help for setup instructions.",
+    "302_go_preferences": "You can also prefix the domain with mirror labels to express a preference or exclude a site. Paths work as on the regular address; for example, append /debian/ to any domain below.",
+    "302_go_prefer_one": "Prefer TUNA; if it cannot be used, another candidate may still be selected.",
+    "302_go_prefer_multiple": "Set an ordered preference list: prefer USTC, then TUNA. Labels farther to the right have higher priority.",
+    "302_go_avoid": "Exclude TUNA completely and select from the remaining candidates, rather than merely lowering its priority.",
     "search": "Experimental Feature: Search Backend",
     "search_description": "Search for a file path inside a repository and continue to a mirror site that provides it. Results and availability can vary with synchronization status.",
     "monitor": "Service status",

src/i18n/zh.json

@@ -59,6 +59,10 @@
     "302_go": "302 跳转后端",
     "302_go_more": "查看镜像帮助文档以使用该后端",
     "302_go_description": "使用统一的镜像地址，并根据网络位置和站点状态跳转到合适的参与站点。具体配置方法请查看镜像帮助。",
+    "302_go_preferences": "还可以在域名前添加镜像站标签，指定偏好或排除特定站点。路径和普通地址相同，例如可在以下域名后继续添加 /debian/。",
+    "302_go_prefer_one": "优先选择 TUNA；无法使用时仍会从其他候选站点中选择。",
+    "302_go_prefer_multiple": "设置有顺序的偏好列表：优先选择 USTC，其次选择 TUNA。越靠后的标签优先级越高。",
+    "302_go_avoid": "完全排除 TUNA，再从其余候选站点中选择，而不只是降低它的优先级。",
     "search": "实验性功能： 搜索后端",
     "search_description": "按仓库中的路径查找文件，并跳转到能够提供该文件的镜像站。搜索结果和可用性可能随同步状态变化。",
     "monitor": "运行状态",

src/ui/About.tsx

@@ -59,6 +59,26 @@ const UrlList = React.memo(({ urls }: { urls: string[] }) => (
   </ul>
 ));
 
+const redirectUrl = (label: string) => {
+  const url = new URL(config.url);
+  url.hostname = `${label}.${url.hostname}`;
+  return url.toString();
+};
+
+const RedirectPattern = React.memo(
+  ({ label, description }: { label: string; description: string }) => {
+    const url = redirectUrl(label);
+    return (
+      <li>
+        <a href={url}>
+          <code>{new URL(url).hostname}</code>
+        </a>
+        <p>{description}</p>
+      </li>
+    );
+  }
+);
+
 export default React.memo(
   ({ site }: { site: { site: Site; parsed: ParsedMirror[] }[] }) => {
     const { t } = useTranslation();
@@ -196,9 +216,21 @@ export default React.memo(
                   <li>
                     <h3>{t("about.302_go")}</h3>
                     <p>{t("about.302_go_description")}</p>
-                    {config.about.includes("mirrors_help") && (
-                      <UrlList urls={[config.mirrors_help_url]} />
-                    )}
+                    <p>{t("about.302_go_preferences")}</p>
+                    <ul className="about-redirect-patterns">
+                      <RedirectPattern
+                        label="tuna"
+                        description={t("about.302_go_prefer_one")}
+                      />
+                      <RedirectPattern
+                        label="tuna-ustc"
+                        description={t("about.302_go_prefer_multiple")}
+                      />
+                      <RedirectPattern
+                        label="avoidtuna"
+                        description={t("about.302_go_avoid")}
+                      />
+                    </ul>
                   </li>
                 )}
               </ul>