feat(client): 反馈 Bug/功能建议 改为直接提交后台（文字+附图）

- feedback_repository + provider：图片上传 /feedback/images、提交 /feedback
- 关于我们的反馈入口改为表单弹窗：多行文字 + 选图上传(缩略图/可删,最多9张)，
  提交到后台，不再走 mailto
- 平台/版本随提交上报（web 安全：defaultTargetPlatform，不引 dart:io）

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/lib/providers/feedback_provider.dart

@@ -0,0 +1,7 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import '../core/api/api_client.dart';
+import '../repositories/feedback_repository.dart';
+
+final feedbackRepositoryProvider = Provider<FeedbackRepository>((ref) {
+  return FeedbackRepository(ref.watch(apiClientProvider));
+});

client/lib/repositories/feedback_repository.dart

@@ -0,0 +1,78 @@
+import 'package:dio/dio.dart';
+import 'package:flutter/foundation.dart';
+import 'package:package_info_plus/package_info_plus.dart';
+import '../core/api/api_client.dart';
+import '../core/exceptions.dart';
+
+class FeedbackRepository {
+  final ApiClient _client;
+  const FeedbackRepository(this._client);
+
+  /// 上传单张图片，返回服务器相对 URL（/images/feedback/...）。
+  Future<String> uploadImage({
+    Uint8List? bytes,
+    String? filePath,
+    String filename = 'image.jpg',
+  }) async {
+    try {
+      final MultipartFile file;
+      if (bytes != null) {
+        file = MultipartFile.fromBytes(bytes, filename: filename);
+      } else {
+        file = await MultipartFile.fromFile(filePath!);
+      }
+      final formData = FormData.fromMap({'file': file});
+      final resp = await _client.post('/feedback/images', data: formData);
+      return (resp.data as Map<String, dynamic>)['url'] as String;
+    } on DioException catch (e) {
+      throw AppException(
+        e.response?.data?['error'] as String? ?? '图片上传失败',
+        statusCode: e.response?.statusCode,
+      );
+    }
+  }
+
+  /// 提交反馈（bug / suggestion），文字 + 图片 URL 列表。
+  Future<void> submit({
+    required String type,
+    required String content,
+    required List<String> images,
+  }) async {
+    String appVersion = '';
+    try {
+      appVersion = (await PackageInfo.fromPlatform()).version;
+    } catch (_) {}
+    try {
+      await _client.post('/feedback', data: {
+        'type': type,
+        'content': content,
+        'images': images,
+        'app_version': appVersion,
+        'platform': _platform(),
+      });
+    } on DioException catch (e) {
+      throw AppException(
+        e.response?.data?['error'] as String? ?? '提交失败',
+        statusCode: e.response?.statusCode,
+      );
+    }
+  }
+
+  String _platform() {
+    if (kIsWeb) return 'web';
+    switch (defaultTargetPlatform) {
+      case TargetPlatform.windows:
+        return 'windows';
+      case TargetPlatform.macOS:
+        return 'macos';
+      case TargetPlatform.android:
+        return 'android';
+      case TargetPlatform.iOS:
+        return 'ios';
+      case TargetPlatform.linux:
+        return 'linux';
+      default:
+        return 'unknown';
+    }
+  }
+}

client/lib/screens/about/about_screen.dart

@@ -1,12 +1,15 @@
+import 'package:file_picker/file_picker.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:intl/intl.dart';
 import 'package:url_launcher/url_launcher.dart';
+import '../../core/config/app_config.dart';
 import '../../core/config/app_info.dart';
 import '../../core/theme/app_theme.dart';
 import '../../core/update/app_updater.dart';
 import '../../core/utils/dialog_util.dart';
+import '../../providers/feedback_provider.dart';
 import '../../providers/license_provider.dart';
 import '../../providers/update_provider.dart';
 
@@ -249,39 +252,191 @@ class _AboutScreenState extends ConsumerState<AboutScreen> {
   }
 
   void _showFeedbackDialog({required bool isBug}) {
-    final ctrl = TextEditingController();
     showAppDialog(
       context: context,
-      builder: (ctx) => AlertDialog(
+      builder: (_) => _FeedbackDialog(type: isBug ? 'bug' : 'suggestion'),
-        title: Text(isBug ? '反馈 Bug' : '功能建议'),
+    );
-        content: SizedBox(
+  }
-          width: 400,
+}
-          child: TextField(
+
-            controller: ctrl,
+/// 反馈表单弹窗：文字 + 附图，直接提交后台。
-            maxLines: 6,
+class _FeedbackDialog extends ConsumerStatefulWidget {
-            decoration: InputDecoration(
+  final String type; // bug / suggestion
-              hintText: isBug ? '请描述问题的复现步骤和预期行为…' : '请描述您希望增加的功能…',
+  const _FeedbackDialog({required this.type});
-              border: const OutlineInputBorder(),
+
+  @override
+  ConsumerState<_FeedbackDialog> createState() => _FeedbackDialogState();
+}
+
+class _FeedbackDialogState extends ConsumerState<_FeedbackDialog> {
+  final _ctrl = TextEditingController();
+  final List<String> _images = []; // 已上传的图片 URL
+  bool _uploading = false;
+  bool _submitting = false;
+
+  static const _maxImages = 9;
+
+  @override
+  void dispose() {
+    _ctrl.dispose();
+    super.dispose();
+  }
+
+  Future<void> _addImages() async {
+    final result = await FilePicker.platform.pickFiles(
+      type: FileType.image,
+      allowMultiple: true,
+      withData: true,
+    );
+    if (result == null) return;
+    setState(() => _uploading = true);
+    try {
+      final repo = ref.read(feedbackRepositoryProvider);
+      for (final f in result.files) {
+        if (_images.length >= _maxImages) break;
+        if (f.bytes == null) continue;
+        final url = await repo.uploadImage(bytes: f.bytes!, filename: f.name);
+        if (!mounted) return;
+        setState(() => _images.add(url));
+      }
+    } catch (e) {
+      if (mounted) {
+        ScaffoldMessenger.of(context)
+            .showSnackBar(SnackBar(content: Text('图片上传失败：$e')));
+      }
+    } finally {
+      if (mounted) setState(() => _uploading = false);
+    }
+  }
+
+  Future<void> _submit() async {
+    if (_ctrl.text.trim().isEmpty && _images.isEmpty) {
+      ScaffoldMessenger.of(context)
+          .showSnackBar(const SnackBar(content: Text('请填写反馈内容或添加图片')));
+      return;
+    }
+    setState(() => _submitting = true);
+    try {
+      await ref.read(feedbackRepositoryProvider).submit(
+            type: widget.type,
+            content: _ctrl.text.trim(),
+            images: _images,
+          );
+      if (!mounted) return;
+      Navigator.pop(context);
+      ScaffoldMessenger.of(context)
+          .showSnackBar(const SnackBar(content: Text('反馈已提交，感谢您的反馈！')));
+    } catch (e) {
+      if (!mounted) return;
+      setState(() => _submitting = false);
+      ScaffoldMessenger.of(context)
+          .showSnackBar(SnackBar(content: Text('提交失败：$e')));
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final isBug = widget.type == 'bug';
+    return AlertDialog(
+      title: Text(isBug ? '反馈 Bug' : '功能建议'),
+      content: SizedBox(
+        width: 440,
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            TextField(
+              controller: _ctrl,
+              maxLines: 6,
+              decoration: InputDecoration(
+                hintText: isBug ? '请描述问题的复现步骤和预期行为…' : '请描述您希望增加的功能…',
+                border: const OutlineInputBorder(),
+              ),
+            ),
+            const SizedBox(height: 12),
+            Wrap(
+              spacing: 8,
+              runSpacing: 8,
+              children: [
+                for (int i = 0; i < _images.length; i++) _thumb(i),
+                if (_images.length < _maxImages) _addButton(),
+              ],
+            ),
+            if (_uploading)
+              const Padding(
+                padding: EdgeInsets.only(top: 8),
+                child: Row(children: [
+                  SizedBox(
+                      width: 14,
+                      height: 14,
+                      child: CircularProgressIndicator(strokeWidth: 2)),
+                  SizedBox(width: 8),
+                  Text('图片上传中…', style: TextStyle(fontSize: 12)),
+                ]),
+              ),
+          ],
+        ),
+      ),
+      actions: [
+        TextButton(
+          onPressed: _submitting ? null : () => Navigator.pop(context),
+          child: const Text('取消'),
+        ),
+        ElevatedButton(
+          onPressed: (_submitting || _uploading) ? null : _submit,
+          child: Text(_submitting ? '提交中…' : '提交'),
+        ),
+      ],
+    );
+  }
+
+  Widget _thumb(int i) {
+    return Stack(
+      clipBehavior: Clip.none,
+      children: [
+        ClipRRect(
+          borderRadius: BorderRadius.circular(6),
+          child: Image.network(
+            '${AppConfig.baseUrl}${_images[i]}',
+            width: 64,
+            height: 64,
+            fit: BoxFit.cover,
+            errorBuilder: (_, __, ___) => Container(
+              width: 64,
+              height: 64,
+              color: Colors.grey.shade200,
+              child: const Icon(Icons.broken_image, size: 20),
             ),
           ),
         ),
-        actions: [
+        Positioned(
-          TextButton(
+          right: -8,
-            onPressed: () => Navigator.pop(ctx),
+          top: -8,
-            child: const Text('取消'),
+          child: GestureDetector(
+            onTap: () => setState(() => _images.removeAt(i)),
+            child: Container(
+              decoration: const BoxDecoration(
+                  color: Colors.black54, shape: BoxShape.circle),
+              padding: const EdgeInsets.all(2),
+              child: const Icon(Icons.close, size: 14, color: Colors.white),
+            ),
           ),
-          ElevatedButton(
+        ),
-            onPressed: () async {
+      ],
-              final subject = Uri.encodeComponent(isBug ? 'Bug反馈' : '功能建议');
+    );
-              final body = Uri.encodeComponent(ctrl.text);
+  }
-              final uri = Uri.parse(
+
-                  'mailto:${AppInfo.email}?subject=$subject&body=$body');
+  Widget _addButton() {
-              if (await canLaunchUrl(uri)) launchUrl(uri);
+    return InkWell(
-              if (ctx.mounted) Navigator.pop(ctx);
+      onTap: _uploading ? null : _addImages,
-            },
+      child: Container(
-            child: const Text('通过邮件发送'),
+        width: 64,
-          ),
+        height: 64,
-        ],
+        decoration: BoxDecoration(
+          border: Border.all(color: Colors.grey.shade400),
+          borderRadius: BorderRadius.circular(6),
+        ),
+        child: const Icon(Icons.add_a_photo_outlined, color: Colors.grey),
       ),
     );
   }