fix(guide): use fitWidth to prevent image stretching + add debug logs

- Change BoxFit.cover to BoxFit.fitWidth for guide page images
- Add screen info logging (resolution, pixel ratio, aspect ratio)
- Add detailed avatar loading logs in frontend and backend
- Log avatarUrl from DB and API response during recovery

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/services/identity-service/src/application/commands/recover-by-mnemonic/recover-by-mnemonic.handler.ts

@@ -43,6 +43,10 @@ export class RecoverByMnemonicHandler {
 
     // 如果头像为空，重新生成一个
     let avatarUrl = account.avatarUrl;
+    this.logger.log(`Account ${command.accountSequence} avatarUrl from DB: ${avatarUrl ? `长度=${avatarUrl.length}` : 'null'}`);
+    if (avatarUrl) {
+      this.logger.log(`Account ${command.accountSequence} avatarUrl前50字符: ${avatarUrl.substring(0, 50)}`);
+    }
     if (!avatarUrl) {
       this.logger.log(`Account ${command.accountSequence} has no avatar, generating new one`);
       avatarUrl = generateRandomAvatarSvg();
@@ -62,7 +66,7 @@ export class RecoverByMnemonicHandler {
     await this.eventPublisher.publishAll(account.domainEvents);
     account.clearDomainEvents();
 
-    return {
+    const result = {
       userId: account.userId.toString(),
       accountSequence: account.accountSequence.value,
       nickname: account.nickname,
@@ -71,5 +75,10 @@ export class RecoverByMnemonicHandler {
       accessToken: tokens.accessToken,
       refreshToken: tokens.refreshToken,
     };
+
+    this.logger.log(`RecoverByMnemonic result - accountSequence: ${result.accountSequence}, nickname: ${result.nickname}`);
+    this.logger.log(`RecoverByMnemonic result - avatarUrl: ${result.avatarUrl ? `长度=${result.avatarUrl.length}` : 'null'}`);
+
+    return result;
   }
 }

frontend/mobile-app/lib/core/services/account_service.dart

@@ -199,11 +199,16 @@ class RecoverAccountResponse {
 
   factory RecoverAccountResponse.fromJson(Map<String, dynamic> json) {
     debugPrint('[AccountService] 解析 RecoverAccountResponse: ${json.keys.toList()}');
+    final avatarUrl = json['avatarUrl'] as String?;
+    debugPrint('[AccountService] RecoverAccountResponse.avatarUrl: ${avatarUrl != null ? "长度=${avatarUrl.length}" : "null"}');
+    if (avatarUrl != null && avatarUrl.isNotEmpty) {
+      debugPrint('[AccountService] RecoverAccountResponse.avatarUrl前50字符: ${avatarUrl.substring(0, avatarUrl.length > 50 ? 50 : avatarUrl.length)}');
+    }
     return RecoverAccountResponse(
       userId: json['userId'] as String,
       userSerialNum: json['accountSequence'] as int,
       username: json['nickname'] as String,
-      avatarSvg: json['avatarUrl'] as String?,
+      avatarSvg: avatarUrl,
       referralCode: json['referralCode'] as String,
       accessToken: json['accessToken'] as String,
       refreshToken: json['refreshToken'] as String,
@@ -884,12 +889,15 @@ class AccountService {
       value: response.username,
     );
 
-    if (response.avatarSvg != null) {
+    if (response.avatarSvg != null && response.avatarSvg!.isNotEmpty) {
       debugPrint('$_tag _saveRecoverAccountData() - 保存 avatarSvg (长度: ${response.avatarSvg!.length})');
+      debugPrint('$_tag _saveRecoverAccountData() - avatarSvg前50字符: ${response.avatarSvg!.substring(0, response.avatarSvg!.length > 50 ? 50 : response.avatarSvg!.length)}');
       await _secureStorage.write(
         key: StorageKeys.avatarSvg,
         value: response.avatarSvg!,
       );
+    } else {
+      debugPrint('$_tag _saveRecoverAccountData() - ⚠️ avatarSvg 为空! response.avatarSvg=${response.avatarSvg}');
     }
 
     // 保存 Token

frontend/mobile-app/lib/features/auth/presentation/pages/guide_page.dart

@@ -38,6 +38,31 @@ class _GuidePageState extends ConsumerState<GuidePage> {
   final PageController _pageController = PageController();
   int _currentPage = 0;
 
+  @override
+  void initState() {
+    super.initState();
+    // 延迟到 build 后获取屏幕信息
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      _logScreenInfo();
+    });
+  }
+
+  /// 打印屏幕信息用于调试
+  void _logScreenInfo() {
+    final mediaQuery = MediaQuery.of(context);
+    final screenSize = mediaQuery.size;
+    final devicePixelRatio = mediaQuery.devicePixelRatio;
+    final physicalSize = screenSize * devicePixelRatio;
+
+    debugPrint('[GuidePage] ========== 屏幕信息 ==========');
+    debugPrint('[GuidePage] 逻辑分辨率: ${screenSize.width.toStringAsFixed(1)} x ${screenSize.height.toStringAsFixed(1)}');
+    debugPrint('[GuidePage] 设备像素比: $devicePixelRatio');
+    debugPrint('[GuidePage] 物理分辨率: ${physicalSize.width.toStringAsFixed(0)} x ${physicalSize.height.toStringAsFixed(0)}');
+    debugPrint('[GuidePage] 屏幕宽高比: ${(screenSize.width / screenSize.height).toStringAsFixed(3)} (${screenSize.width.toStringAsFixed(0)}:${screenSize.height.toStringAsFixed(0)})');
+    debugPrint('[GuidePage] 图片设计比例: 0.5625 (1080:1920 = 9:16)');
+    debugPrint('[GuidePage] ================================');
+  }
+
   // 向导页1-5的数据 (第5页为欢迎加入页)
   // 支持 png、jpg、webp 等格式
   final List<GuidePageData> _guidePages = const [
@@ -121,37 +146,50 @@ class _GuidePageState extends ConsumerState<GuidePage> {
   }
 
   /// 构建向导页 (页面1-4) - 全屏背景图片，无文字
+  /// 使用 BoxFit.fitWidth 保持图片原始比例，不拉伸文字
   Widget _buildGuidePage(GuidePageData data, int index) {
-    return Stack(
+    debugPrint('[GuidePage] _buildGuidePage() - 页面 ${index + 1}, 图片: ${data.imagePath}');
-      fit: StackFit.expand,
+    return Container(
-      children: [
+      color: Colors.black, // 如果图片不够高，上下用黑色填充
-        // 全屏背景图片
+      child: Stack(
-        if (data.imagePath != null)
+        fit: StackFit.expand,
-          Image.asset(
+        children: [
-            data.imagePath!,
+          // 全屏背景图片 - 使用 fitWidth 保持宽高比
-            fit: BoxFit.cover,
+          if (data.imagePath != null)
-            width: double.infinity,
+            LayoutBuilder(
-            height: double.infinity,
+              builder: (context, constraints) {
-            errorBuilder: (context, error, stackTrace) {
+                debugPrint('[GuidePage] 页面 ${index + 1} 容器尺寸: ${constraints.maxWidth.toStringAsFixed(1)} x ${constraints.maxHeight.toStringAsFixed(1)}');
-              return Container(
+                debugPrint('[GuidePage] 页面 ${index + 1} 使用 BoxFit.fitWidth');
-                color: const Color(0xFFFFF8E7),
+                return Center(
-                child: _buildPlaceholderImage(index),
+                  child: Image.asset(
-              );
+                    data.imagePath!,
-            },
+                    fit: BoxFit.fitWidth,
-          )
+                    width: double.infinity,
-        else
+                    errorBuilder: (context, error, stackTrace) {
-          Container(
+                      debugPrint('[GuidePage] 页面 ${index + 1} 图片加载失败: $error');
-            color: const Color(0xFFFFF8E7),
+                      return Container(
-            child: _buildPlaceholderImage(index),
+                        color: const Color(0xFFFFF8E7),
+                        child: _buildPlaceholderImage(index),
+                      );
+                    },
+                  ),
+                );
+              },
+            )
+          else
+            Container(
+              color: const Color(0xFFFFF8E7),
+              child: _buildPlaceholderImage(index),
+            ),
+          // 底部页面指示器
+          Positioned(
+            left: 0,
+            right: 0,
+            bottom: 80.h,
+            child: _buildPageIndicator(),
           ),
-        // 底部页面指示器
+        ],
-        Positioned(
+      ),
-          left: 0,
-          right: 0,
-          bottom: 80.h,
-          child: _buildPageIndicator(),
-        ),
-      ],
     );
   }
 
@@ -385,39 +423,42 @@ class _WelcomePageContentState extends ConsumerState<_WelcomePageContent> {
   Widget build(BuildContext context) {
     return GestureDetector(
       onTap: () => FocusScope.of(context).unfocus(),
-      child: Stack(
+      child: Container(
-        fit: StackFit.expand,
+        color: Colors.black, // 如果图片不够高，上下用黑色填充
-        children: [
+        child: Stack(
-          // 全屏背景图片
+          fit: StackFit.expand,
-          if (widget.backgroundImage != null)
+          children: [
-            Image.asset(
+            // 全屏背景图片 - 使用 fitWidth 保持宽高比
-              widget.backgroundImage!,
+            if (widget.backgroundImage != null)
-              fit: BoxFit.cover,
+              Center(
-              width: double.infinity,
+                child: Image.asset(
-              height: double.infinity,
+                  widget.backgroundImage!,
-              errorBuilder: (context, error, stackTrace) {
+                  fit: BoxFit.fitWidth,
-                return Container(
+                  width: double.infinity,
-                  color: const Color(0xFFFFF8E7),
+                  errorBuilder: (context, error, stackTrace) {
-                );
+                    return Container(
-              },
+                      color: const Color(0xFFFFF8E7),
-            )
+                    );
-          else
+                  },
+                ),
+              )
+            else
+              Container(
+                color: const Color(0xFFFFF8E7),
+              ),
+            // 半透明遮罩，让内容更清晰
             Container(
-              color: const Color(0xFFFFF8E7),
+              decoration: BoxDecoration(
-            ),
+                gradient: LinearGradient(
-          // 半透明遮罩，让内容更清晰
+                  begin: Alignment.topCenter,
-          Container(
+                  end: Alignment.bottomCenter,
-            decoration: BoxDecoration(
+                  colors: [
-              gradient: LinearGradient(
+                    Colors.black.withValues(alpha: 0.3),
-                begin: Alignment.topCenter,
+                    Colors.black.withValues(alpha: 0.6),
-                end: Alignment.bottomCenter,
+                  ],
-                colors: [
+                ),
-                  Colors.black.withValues(alpha: 0.3),
-                  Colors.black.withValues(alpha: 0.6),
-                ],
               ),
             ),
-          ),
           // 内容区域
           SafeArea(
             child: LayoutBuilder(
@@ -526,6 +567,7 @@ class _WelcomePageContentState extends ConsumerState<_WelcomePageContent> {
             ),
           ),
         ],
+        ),
       ),
     );
   }