feat: 对齐常驻商城与七鱼客服交互

- 同步商城 H5 登录态与原生 token
- 完善商城/原生 tab 切换、动画及返回交互
- 修复七鱼客服键盘避让和状态栏恢复
- 调整开屏跳过按钮与登录入口交互

test/features/web/mall_web_host_test.dart

@@ -0,0 +1,62 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:jinzhi_flutter_app/features/web/presentation/mall_web_host.dart';
+
+void main() {
+  test('loading only covers the WebView before its first page', () {
+    expect(
+      shouldShowMallLoading(
+        hasError: false,
+        hasDisplayedPage: false,
+        progress: 0,
+      ),
+      isTrue,
+    );
+    expect(
+      shouldShowMallLoading(
+        hasError: false,
+        hasDisplayedPage: true,
+        progress: 0,
+      ),
+      isFalse,
+    );
+    expect(
+      shouldShowMallLoading(
+        hasError: true,
+        hasDisplayedPage: false,
+        progress: 0,
+      ),
+      isFalse,
+    );
+  });
+
+  test('only Android Qiyu pages reserve keyboard space for the WebView', () {
+    expect(
+      qiyuWebViewBottomInset(
+        isShowingQiyuPage: true,
+        platform: TargetPlatform.android,
+        keyboardInset: 336,
+        isWeb: false,
+      ),
+      336,
+    );
+    expect(
+      qiyuWebViewBottomInset(
+        isShowingQiyuPage: false,
+        platform: TargetPlatform.android,
+        keyboardInset: 336,
+        isWeb: false,
+      ),
+      0,
+    );
+    expect(
+      qiyuWebViewBottomInset(
+        isShowingQiyuPage: true,
+        platform: TargetPlatform.iOS,
+        keyboardInset: 336,
+        isWeb: false,
+      ),
+      0,
+    );
+  });
+}