修复白屏BUG、UI 边界溢出 BUG

lib/features/profile/presentation/avatar_image.dart

@@ -0,0 +1,19 @@
+import 'dart:io';
+
+import 'package:flutter/material.dart';
+
+import 'package:arcx/core/constants/app_defaults.dart';
+import 'package:arcx/data/local/models/models.dart';
+
+/// Resolves a profile avatar to a local file when present, otherwise the
+/// default asset. Missing local files fall back safely (no FileImage crash).
+ImageProvider resolveAvatarImage(UserProfile? profile) {
+  final path = profile?.avatarLocalPath?.trim();
+  if (profile?.avatarSource == AvatarSource.localFile &&
+      path != null &&
+      path.isNotEmpty &&
+      File(path).existsSync()) {
+    return FileImage(File(path));
+  }
+  return const AssetImage(AppDefaults.defaultAvatarAssetPath);
+}