fix: 接口出错时只显示 hub 的中文文案，反代错误页与断网按状态说明

src/App.tsx

@@ -98,11 +98,9 @@ export default function App() {
   const open = useNodeRoute()
 
   const loadMe = useCallback(() => {
-    // `|| "..."`: HTTP/2 has no statusText, so a bodiless 502 from a proxy arrives
-    // as "" and would otherwise render as still loading, with no retry button.
     return api<Me>("/me")
       .then((next) => { setMe(next); setMeError("") })
-      .catch((e: Error) => setMeError(e.message || "网络错误"))
+      .catch((e: Error) => setMeError(e.message))
   }, [])
 
   useEffect(() => {

src/components/NodeDetail.tsx

@@ -137,10 +137,7 @@ function useHistory(id: number, hours: number, series: "metrics" | "ping") {
     api<History>(`/nodes/${id}/metrics?hours=${hours}&points=${points}&series=${series}`)
       .then((next) => { if (active) setData(next) })
       .catch((e: Error) => {
-        // `|| "..."` as in App.tsx: HTTP/2 dropped statusText, so a bodiless
-        // failure from a proxy arrives as the empty string and renders as no
-        // error.
-        if (active) { setFailed(e.message || "网络错误"); setData({ metrics: [], ping: [], probes: {} }) }
+        if (active) { setFailed(e.message); setData({ metrics: [], ping: [], probes: {} }) }
       })
     return () => { active = false }
   }, [id, hours, series, attempt])

src/lib/api.ts

@@ -83,13 +83,35 @@ class ApiError extends Error {
   }
 }
 
+/**
+ * Every error the hub answers is one line of plain text written for the reader.
+ * Anything else came from something in front of it -- a proxy's error page, a
+ * CDN's challenge, an empty 502 -- and is described by its status instead.
+ */
+async function failure(res: Response): Promise<ApiError> {
+  const text = res.headers.get("content-type")?.startsWith("text/plain") ? (await res.text()).trim() : ""
+  return new ApiError(
+    res.status,
+    text || (res.status >= 500 ? `服务暂时无法访问（HTTP ${res.status}），稍后再试` : `请求被拦截（HTTP ${res.status}），稍后再试`),
+  )
+}
+
 export async function api<T>(path: string, init?: RequestInit): Promise<T> {
-  const res = await fetch(`/api${path}`, {
-    ...init,
-    headers: init?.body ? { "content-type": "application/json", ...init?.headers } : init?.headers,
+  let res: Response
+  try {
+    res = await fetch(`/api${path}`, {
+      ...init,
+      headers: init?.body ? { "content-type": "application/json", ...init?.headers } : init?.headers,
+    })
+  } catch {
+    throw new ApiError(0, "网络连接失败，稍后再试")
+  }
+  if (!res.ok) throw await failure(res)
+  if (res.status === 204) return undefined as T
+  // A 200 carrying HTML is a proxy's page, not the hub's JSON.
+  return res.json().catch(() => {
+    throw new ApiError(res.status, "收到的不是状态数据，稍后再试")
   })
-  if (!res.ok) throw new ApiError(res.status, (await res.text()) || res.statusText)
-  return res.status === 204 ? (undefined as T) : res.json()
 }
 
 /** A malformed report must not remove every other node from the page. */