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/test/config_test.dart

@@ -0,0 +1,16 @@
+import 'package:changlian/config.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  test('默认公网地址走 HTTPS/WSS 且不含测试 IP', () {
+    expect(serverHost, 'jxd.jinniu.ink');
+    expect(useTls, isTrue);
+    expect(apiAddr, 'https://jxd.jinniu.ink');
+    expect(wsAddr, 'wss://jxd.jinniu.ink/msg_gateway');
+    expect(livekitUrl, 'wss://jxd.jinniu.ink/livekit');
+    expect(authApiBase, 'https://jxd.jinniu.ink/account');
+    expect(apiAddr, isNot(contains('154.37')));
+    expect(wsAddr, isNot(contains('154.37')));
+    expect(jpushAppKey, '95fc2352648a7d4568ac8d72');
+  });
+}