feat(auth): clarify login identity and speed up mobile entry

h5/js/account-client.js

@@ -5,11 +5,19 @@ window.AccountClient = (function () {
   function read(name) { try { return localStorage.getItem(name || key); } catch (_) { return null; } }
   function rememberKind() { try { if (user) localStorage.setItem(kindKey, user.kind); } catch (_) {} }
   function request(url, data) {
+    var controller = new AbortController();
+    // Bound only authentication waits. Full report snapshots contain photos and
+    // must retain their existing download budget on a slow mobile connection.
+    var timer = url.indexOf('api/auth/') === 0 ? setTimeout(function () { controller.abort(); }, 12000) : null;
     return fetch(url, { credentials: 'same-origin', method: data ? 'POST' : 'GET',
+      signal: controller.signal,
       headers: data ? { 'Content-Type': 'application/json' } : {},
       body: data ? JSON.stringify(data) : undefined }).then(function (r) {
       return r.json().then(function (v) { if (!r.ok || !v.ok) throw new Error(v.message || '请求失败'); return v; });
-    });
+    }).catch(function (error) {
+      if (error.name === 'AbortError') throw new Error('网络响应超时，请检查网络后重试');
+      throw error;
+    }).finally(function () { clearTimeout(timer); });
   }
   function browser(consent) {
     return request('api/auth/browser', { consent: consent, token: read() }).then(function (v) {