feat: 旅行伙伴发放与编组、修复退登卡死、优化宽屏布局、加 CI

自动退出登录卡死：_performLogoutAndExit 只 pop() 一层，而解锁/收藏品页是 push
在 HomePage 之上的，退登后被弹回「风险」hub，同时 _loggingOut 仍为 true，
PopScope(canPop:false) + 返回键转圈形成死局。改为 popUntil(isFirst)。

旅行伙伴发不了：它是 ItemKind.Character = 9，与搭档 Partner = 10 是两种东西，
原先收藏品的类型列表 [1,2,3,10,11,12] 里根本没有 9。按客户端实现，角色不走
userItemList(ExportUserItems 不导出 itemKind 9)，而是
upsertUserAll.userCharacterList 的 {characterId, level, awakening, useCount}，
配 isNewCharacterList 一行一字符。新增发放与 5 槽 charaSlot 编组页，
含「把槽 0 复制到其他槽位」，并校验所选角色确为已拥有或本次待发放。

宽屏布局：各页只有 ConstrainedBox 限宽、没有居中容器，1440 窗口下内容贴左、
右侧大片空白。抽出 responsiveBody 统一居中；B50 预览改用按宽度适配
(InteractiveViewer constrained:false + FittedBox fitWidth)，横屏下不再被
contain 缩成中间一小块，导出仍是原始 1762x1850。

CI：.github/workflows/build.yml 先跑 analyze+test 作为门槛，再产出
Windows exe、Android apk、iOS 未签名 ipa(macOS runner，无证书故不可安装)。
README 从 Flutter 模板改写为实际文档，含 path_provider/jni 与 JBR jlink
两个构建环境坑的说明。

test/user_all_patch_test.dart

@@ -0,0 +1,116 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:ichino/config/title_server_config.dart';
+import 'package:ichino/models/user_character.dart';
+import 'package:ichino/services/user_all_payload_builder.dart';
+
+const _config = TitleServerConfig(
+  titleServerUrl: 'http://127.0.0.1:9999',
+  aesKey: '0123456789abcdef',
+  aesIv: '0123456789abcdef',
+  clientId: 'A63E01C2805',
+);
+
+Map<String, dynamic> _buildPacket(UserAllPayloadBuilder builder) =>
+    builder.build(
+      userId: 42,
+      loginId: 7,
+      loginDateTime: 1700000000,
+      musicData: const {
+        'musicId': 11538,
+        'level': 0,
+        'playCount': 1,
+        'achievement': 0,
+        'comboStatus': 0,
+        'syncStatus': 0,
+        'deluxscoreMax': 0,
+        'scoreRank': 0,
+        'extNum1': 0,
+      },
+      generalUserInfo: const {},
+    );
+
+Map<String, dynamic> _upsert(Map<String, dynamic> packet) =>
+    packet['upsertUserAll'] as Map<String, dynamic>;
+
+void main() {
+  group('旅行伙伴 userCharacterList patch', () {
+    test('写入 4 字段行并按行数生成 isNewCharacterList', () {
+      final builder = UserAllPayloadBuilder(_config);
+      final packet = _buildPacket(builder);
+
+      builder.applyCharacterListPatch(packet, characters: [
+        {'characterId': 1001, 'level': 1, 'awakening': 0, 'useCount': 0},
+        {'characterId': 1002, 'level': 3, 'awakening': 1, 'useCount': 9},
+      ]);
+
+      final upsert = _upsert(packet);
+      expect(upsert['userCharacterList'], hasLength(2));
+      expect(upsert['isNewCharacterList'], '11');
+      final first = (upsert['userCharacterList'] as List).first
+          as Map<String, dynamic>;
+      // 客户端 UserCharacter 结构只有这 4 个字段，多一个都可能被拒。
+      expect(first.keys.toSet(), {
+        'characterId',
+        'level',
+        'awakening',
+        'useCount',
+      });
+    });
+
+    test('空列表时 isNewCharacterList 为空串', () {
+      final builder = UserAllPayloadBuilder(_config);
+      final packet = _buildPacket(builder);
+      builder.applyCharacterListPatch(packet, characters: []);
+      expect(_upsert(packet)['isNewCharacterList'], '');
+    });
+  });
+
+  group('charaSlot 编组 patch', () {
+    test('槽位补齐到 5 并同步 playlog 的 characterId1..5', () {
+      final builder = UserAllPayloadBuilder(_config);
+      final packet = _buildPacket(builder);
+
+      builder.applyCharaSlotPatch(packet, charaSlot: const [1001]);
+
+      final userData = (_upsert(packet)['userData'] as List).first
+          as Map<String, dynamic>;
+      expect(userData['charaSlot'], [1001, 0, 0, 0, 0]);
+
+      final playlog = (packet['userPlaylogList'] as List).first
+          as Map<String, dynamic>;
+      expect(playlog['characterId1'], 1001);
+      expect(playlog['characterId2'], 0);
+    });
+
+    test('超过 5 个槽位被截断', () {
+      expect(
+        normalizeCharaSlot(const [1, 2, 3, 4, 5, 6, 7]),
+        [1, 2, 3, 4, 5],
+      );
+    });
+
+    test('一键复制槽 0 到其余槽位', () {
+      final slots = normalizeCharaSlot(const [1001, 0, 0, 0, 0]);
+      final copied = normalizeCharaSlot([
+        for (var i = 0; i < 5; i++) slots[0],
+      ]);
+      expect(copied, [1001, 1001, 1001, 1001, 1001]);
+    });
+  });
+
+  group('收藏品 userItemList patch', () {
+    test('多行道具与 isNewItemList 位数一致', () {
+      final builder = UserAllPayloadBuilder(_config);
+      final packet = _buildPacket(builder);
+
+      builder.applyItemListPatch(packet, items: [
+        {'itemKind': 9, 'itemId': 1001, 'stock': 1, 'isValid': true},
+        {'itemKind': 10, 'itemId': 2002, 'stock': 1, 'isValid': true},
+      ]);
+
+      final upsert = _upsert(packet);
+      expect(upsert['userItemList'], hasLength(2));
+      expect(upsert['isNewItemList'], '11');
+    });
+  });
+}