feat(mobile-app): use real user data in profile page

- Load username, serial number, and avatar from account service
- Display SVG avatar from backend instead of static image
- Show loading state while fetching user data

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

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

frontend/mobile-app/lib/features/profile/presentation/pages/profile_page.dart

@@ -1,7 +1,9 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_svg/flutter_svg.dart';
 import 'package:go_router/go_router.dart';
+import '../../../../core/di/injection_container.dart';
 import '../../../../routes/route_paths.dart';
 import 'dart:async';
 
@@ -15,9 +17,10 @@ class ProfilePage extends ConsumerStatefulWidget {
 }
 
 class _ProfilePageState extends ConsumerState<ProfilePage> {
-  // 模拟用户数据
-  final String _nickname = '用户昵称';
-  final String _serialNumber = '12345678';
+  // 用户数据（从存储加载）
+  String _nickname = '加载中...';
+  String _serialNumber = '--';
+  String? _avatarSvg;
   final String _referrerSerial = '87654321';
   final String _community = '星空社区';
   final String _parentCommunity = '银河社区';
@@ -58,6 +61,24 @@ class _ProfilePageState extends ConsumerState<ProfilePage> {
   void initState() {
     super.initState();
     _startCountdown();
+    _loadUserData();
+  }
+
+  /// 加载用户数据
+  Future<void> _loadUserData() async {
+    final accountService = ref.read(accountServiceProvider);
+
+    final username = await accountService.getUsername();
+    final serialNum = await accountService.getUserSerialNum();
+    final avatarSvg = await accountService.getAvatarSvg();
+
+    if (mounted) {
+      setState(() {
+        _nickname = username ?? '未设置昵称';
+        _serialNumber = serialNum?.toString() ?? '--';
+        _avatarSvg = avatarSvg;
+      });
+    }
   }
 
   @override
@@ -261,17 +282,18 @@ class _ProfilePageState extends ConsumerState<ProfilePage> {
             ),
             child: ClipRRect(
               borderRadius: BorderRadius.circular(40),
-              child: Image.asset(
-                'assets/images/Button@2x.png',
-                fit: BoxFit.cover,
-                errorBuilder: (context, error, stackTrace) {
-                  return const Icon(
-                    Icons.person,
-                    size: 40,
-                    color: Color(0xFF8B5A2B),
-                  );
-                },
-              ),
+              child: _avatarSvg != null
+                  ? SvgPicture.string(
+                      _avatarSvg!,
+                      width: 80,
+                      height: 80,
+                      fit: BoxFit.cover,
+                    )
+                  : const Icon(
+                      Icons.person,
+                      size: 40,
+                      color: Color(0xFF8B5A2B),
+                    ),
             ),
           ),
         ),