fix: add missing test env

Author: hmd-ali

.env.test

@@ -16,6 +16,7 @@ SERVER_ID=your-server-id
 GUIDES_CHANNEL_ID=your-guide-channel-id
 ADVENT_OF_CODE_CHANNEL_ID=your_advent_of_code_forum_channel_id_here
 REPEL_LOG_CHANNEL_ID=your-repel-log-channel-id
+SHOWCASE_CHANNEL_ID=your-showcase-forum-channel-id
 
 # Role IDs (from your dev server)
 REPEL_ROLE_ID=your-repel-role-id