fix：对齐金值的报名验证，商城入口逻辑对齐

test/features/mall/mall_tab_config_test.dart

@@ -1,3 +1,5 @@
+import 'dart:convert';
+
 import 'package:flutter_test/flutter_test.dart';
 import 'package:jinzhi_flutter_app/features/mall/application/mall_tab_config.dart';
 
@@ -41,4 +43,69 @@ void main() {
     expect(nativeApp.opensInApp, isFalse);
     expect(external.opensInApp, isFalse);
   });
+
+  test('shows the first-install promo only for a configured mall entry', () {
+    const configured = MallTabConfig(
+      enabled: true,
+      url: 'https://mall.example.com',
+      entryPromoEnabled: true,
+      entryBadgeText: '新人礼',
+      entryTipTitle: '新人礼：￥360 铂金订购券',
+      entryTipBody: '点击这里进商城',
+    );
+    const disabled = MallTabConfig(
+      enabled: true,
+      url: 'https://mall.example.com',
+      entryPromoEnabled: false,
+      entryTipTitle: '新人礼',
+    );
+
+    expect(configured.showsEntryBadge, isTrue);
+    expect(configured.showsEntryTip, isTrue);
+    expect(disabled.showsEntryBadge, isFalse);
+    expect(disabled.showsEntryTip, isFalse);
+  });
+
+  test('parses the server-provided mall entry promotion fields', () {
+    final creative = <int>[
+      ..._stringField(9, 'https://mall.example.com'),
+      ..._boolField(16, true),
+      ..._stringField(17, '新人礼'),
+      ..._stringField(18, '新人礼：￥360 铂金订购券'),
+      ..._stringField(19, '点击这里进商城'),
+    ];
+    final config = parseMallTabConfigResponse(<int>[
+      ..._boolField(1, true),
+      ..._bytesField(2, creative),
+    ]);
+
+    expect(config.showsEntryBadge, isTrue);
+    expect(config.entryBadgeText, '新人礼');
+    expect(config.entryTipTitle, '新人礼：￥360 铂金订购券');
+    expect(config.entryTipBody, '点击这里进商城');
+  });
+}
+
+List<int> _stringField(int tag, String value) =>
+    _bytesField(tag, utf8.encode(value));
+
+List<int> _bytesField(int tag, List<int> value) => <int>[
+  ..._varint((tag << 3) | 2),
+  ..._varint(value.length),
+  ...value,
+];
+
+List<int> _boolField(int tag, bool value) => <int>[
+  ..._varint(tag << 3),
+  value ? 1 : 0,
+];
+
+List<int> _varint(int value) {
+  final bytes = <int>[];
+  while (value > 127) {
+    bytes.add((value & 127) | 128);
+    value >>= 7;
+  }
+  bytes.add(value);
+  return bytes;
 }