feat(mobile,deploy): 接入安卓极光与华为通道并准备公网部署配置

客户端默认指向 jxd.jinniu.ink 的 HTTPS/WSS；登录后把 OpenIM userID 设为极光 alias。
华为 agconnect-services.json 不伪造、不入库。Master Secret 只从服务器文件注入。

Co-authored-by: multica-agent <github@multica.ai>

mobile/lib/services/message_send_service.dart

@@ -50,7 +50,12 @@ class MessageSendService {
         message: message,
         userID: isGroup ? null : peer,
         groupID: isGroup ? groupID : null,
-        offlinePushInfo: OfflinePushInfo(),
+        offlinePushInfo: OfflinePushInfo(
+          title: '畅联',
+          desc: '你收到一条新消息',
+          iOSBadgeCount: true,
+          iOSPushSound: '+1',
+        ),
       );
       return sent;
     } catch (e) {