feat: 公开商品页重设计 + web 上传修复 + 二维码配置

- 公开商品页（/product/:uuid）全面重设计：全宽正方形图片轮播、
  左右滑动切图、点击放大全屏查看、商品参数含描述、页脚贴底
- 修复 Flutter web 文件上传无反应（path→bytes）
- 修复 web 路由空白页（usePathUrlStrategy + 单层 MaterialApp.router）
- 二维码 URL 改为从 STORAGE_PUBLIC_URL 环境变量读取
- 新增 PUBLIC_URL dart-define → AppConfig.publicBaseUrl
- 新增 CI/CD workflows + NAS runner compose 配置
- seed S001 补充商品描述字段

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/lib/screens/products/product_detail_screen.dart

@@ -1,5 +1,6 @@
 import 'dart:typed_data';
 import 'package:file_picker/file_picker.dart';
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
@@ -91,16 +92,20 @@ class _ProductDetailScreenState extends ConsumerState<ProductDetailScreen> {
     final result = await FilePicker.platform.pickFiles(
       type: FileType.image,
       allowMultiple: false,
+      withData: true,
     );
     if (result == null || result.files.isEmpty) return;
-    final path = result.files.first.path;
-    if (path == null) return;
+    final file = result.files.first;
+    final String? filePath = kIsWeb ? null : file.path;
+    final fileBytes = file.bytes;
+    if (filePath == null && fileBytes == null) return;
 
     setState(() => _uploading = true);
     try {
       final img = await ref
           .read(productRepositoryProvider)
-          .uploadImage(_product!.id, path);
+          .uploadImage(_product!.id, filePath,
+              bytes: fileBytes, fileName: file.name);
       _updateImages([..._product!.images, img]);
       if (mounted) {
         ScaffoldMessenger.of(context).showSnackBar(
@@ -357,7 +362,7 @@ class _ProductDetailScreenState extends ConsumerState<ProductDetailScreen> {
   }
 
   Widget _buildPublicLinkSection(Product p) {
-    final publicUrl = 'https://jiu.51yanmei.com/product/${p.publicId}';
+    final publicUrl = '${AppConfig.publicBaseUrl}/product/${p.publicId}';
     return Card(
       elevation: 0,
       shape: RoundedRectangleBorder(