fix(conversations): filter canal='turnero' out of individual chat message views

get_user_messages.php and get_recent_messages.php now exclude canal='turnero'
so the main bot chat only shows bot messages even for users who also have
turnero conversations.

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

api/get_recent_messages.php

@@ -27,7 +27,7 @@ try {
             u.name
          FROM conversations c
          JOIN users u ON c.user_id = u.id
-         WHERE c.content IS NOT NULL AND c.content != ''
+         WHERE c.content IS NOT NULL AND c.content != '' AND (c.canal IS NULL OR c.canal = 'bot')
          ORDER BY c.created_at DESC
          LIMIT 10"
     );

api/get_user_messages.php

@@ -74,9 +74,9 @@ try {
             c.reply_to_message_id as reply_to_message_id,
             c.reaction_emoji as reaction_emoji,
             c.reaction_to_message_id as reaction_to_message_id
-         FROM conversations c 
+         FROM conversations c
          LEFT JOIN users u ON c.user_id = u.id
-         WHERE c.user_id = :user_id";
+         WHERE c.user_id = :user_id AND (c.canal IS NULL OR c.canal = 'bot')";
 
     // Soporte para paginación estable: before (timestamp) y before_id (id del mensaje más antiguo del bloque)
     $beforeId = isset($_GET['before_id']) ? intval($_GET['before_id']) : null;
@@ -157,8 +157,8 @@ try {
                 mime_type,
                 status,
                 created_at
-             FROM conversations 
+             FROM conversations
-             WHERE user_id = :user_id
+             WHERE user_id = :user_id AND (canal IS NULL OR canal = 'bot')
              ORDER BY created_at ASC",
             ['user_id' => $userId]
         );