feat: add RssItemMeta.fromNewsItem adapter factory

lib/widgets/news_card.dart

@@ -1,6 +1,8 @@
 import 'package:flutter/material.dart';
 import 'package:url_launcher/url_launcher.dart';
 
+import '../data/models/news_item.dart';
+
 class RssItemMeta {
   final int id;
   final String title;
@@ -29,6 +31,15 @@ class RssItemMeta {
             : null,
       );
 
+  factory RssItemMeta.fromNewsItem(NewsItem item) => RssItemMeta(
+        id: item.id,
+        title: item.title,
+        url: item.url,
+        source: item.source,
+        snippet: item.snippet,
+        publishedAt: item.publishedAt,
+      );
+
   String get relativeDate {
     if (publishedAt == null) return '';
     final diff = DateTime.now().difference(publishedAt!);
@@ -42,12 +53,14 @@ class NewsCard extends StatelessWidget {
   final RssItemMeta item;
   final String? reaction; // 'up' | 'down' | null
   final void Function(int itemId, String reaction) onReaction;
+  final VoidCallback? onDiscuss;
 
   const NewsCard({
     super.key,
     required this.item,
     required this.reaction,
     required this.onReaction,
+    this.onDiscuss,
   });
 
   Future<void> _openUrl() async {
@@ -127,9 +140,8 @@ class NewsCard extends StatelessWidget {
               ),
             ],
             const SizedBox(height: 8),
-            // Reaction buttons
+            // Actions row: reactions + discuss
             Row(
-              mainAxisSize: MainAxisSize.min,
               children: [
                 _ReactionButton(
                   emoji: '👍',
@@ -142,6 +154,10 @@ class NewsCard extends StatelessWidget {
                   active: reaction == 'down',
                   onTap: () => onReaction(item.id, 'down'),
                 ),
+                if (onDiscuss != null) ...[
+                  const Spacer(),
+                  _DiscussButton(onTap: onDiscuss!),
+                ],
               ],
             ),
           ],
@@ -151,6 +167,34 @@ class NewsCard extends StatelessWidget {
   }
 }
 
+class _DiscussButton extends StatelessWidget {
+  final VoidCallback onTap;
+  const _DiscussButton({required this.onTap});
+
+  @override
+  Widget build(BuildContext context) {
+    final scheme = Theme.of(context).colorScheme;
+    return GestureDetector(
+      onTap: onTap,
+      child: Container(
+        padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 3),
+        decoration: BoxDecoration(
+          border: Border.all(color: scheme.primary.withValues(alpha: 0.5)),
+          borderRadius: BorderRadius.circular(6),
+        ),
+        child: Text(
+          'Discuss',
+          style: TextStyle(
+            fontSize: 12,
+            fontWeight: FontWeight.w600,
+            color: scheme.primary,
+          ),
+        ),
+      ),
+    );
+  }
+}
+
 class _ReactionButton extends StatelessWidget {
   final String emoji;
   final bool active;