feat：分享功能

lib/features/news/presentation/news_detail_page.dart

@@ -2,6 +2,9 @@ import 'package:flutter/material.dart';
 import 'package:hooks_riverpod/hooks_riverpod.dart';
 import 'package:shadcn_ui/shadcn_ui.dart';
 
+import '../../../common/config/app_h5_urls.dart';
+import '../../../common/util/share_util.dart';
+import '../../../common/widgets/app_toast.dart';
 import '../../../common/widgets/prototype_ui.dart';
 import '../application/news_controller.dart';
 
@@ -35,6 +38,33 @@ class NewsDetailPage extends ConsumerWidget {
           item.metal.label,
           style: const TextStyle(fontSize: 17, fontWeight: FontWeight.w600),
         ),
+        actions: [
+          Builder(
+            builder: (buttonContext) => IconButton(
+              onPressed: () async {
+                final shareText = [
+                  item.title,
+                  '${item.source} · ${_timeLabel(item.publishedAt)} · ${item.metal.label}',
+                  item.summary,
+                  '打开金值查看：${AppH5Urls.baseUrl}/news/detail?id=${item.id}',
+                ].join('\n');
+                try {
+                  await sharePlainText(
+                    text: shareText,
+                    subject: item.title,
+                    sharePositionOrigin: shareOriginForContext(buttonContext),
+                  );
+                } catch (e) {
+                  debugPrint('share news failed: $e');
+                  if (!context.mounted) return;
+                  await toastInfo(msg: '分享失败');
+                }
+              },
+              icon: const Icon(Icons.ios_share_outlined, size: 20),
+              color: const Color(0xFF8A8780),
+            ),
+          ),
+        ],
       ),
       body: SafeArea(
         child: ListView(