fix: Resolve duplicate interaction detection and add usernames

- Add processed_ids set to prevent duplicate inserts when a tweet is
  both a mention and a comment (same external_id)
- Enhance get_mentions() to fetch usernames via user expansions
- Update fetch_interactions to prefer username over numeric author_id

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/publishers/x_publisher.py

@@ -189,22 +189,31 @@ class XPublisher(BasePublisher):
             me = self.client.get_me()
             user_id = me.data.id
 
-            # Obtener menciones
+            # Obtener menciones con información de usuarios
             mentions = self.client.get_users_mentions(
                 id=user_id,
                 since_id=since_id,
                 max_results=50,
-                tweet_fields=['created_at', 'author_id', 'conversation_id']
+                tweet_fields=['created_at', 'author_id', 'conversation_id'],
+                user_fields=['username'],
+                expansions=['author_id']
             )
 
             if not mentions.data:
                 return []
 
+            # Crear mapa de usuarios para obtener usernames
+            users_map = {}
+            if mentions.includes and 'users' in mentions.includes:
+                for user in mentions.includes['users']:
+                    users_map[str(user.id)] = user.username
+
             return [
                 {
                     "id": str(tweet.id),
                     "text": tweet.text,
                     "author_id": str(tweet.author_id),
+                    "username": users_map.get(str(tweet.author_id), str(tweet.author_id)),
                     "created_at": tweet.created_at.isoformat() if tweet.created_at else None
                 }
                 for tweet in mentions.data