fix: use discord_consolidation user ID for consolidation WS connection

Cat's WebSocket handler returns HTTP 500 for user IDs without the
'discord_' prefix. The consolidation WS was using 'system_consolidation'
which failed immediately with WSServerHandshakeError (500). Changed to
'discord_consolidation' which connects successfully.

bot/utils/cat_client.py

@@ -590,7 +590,7 @@ class CatAdapter:
         """
         try:
             ws_base = self._base_url.replace("http://", "ws://").replace("https://", "wss://")
-            ws_url = f"{ws_base}/ws/system_consolidation"
+            ws_url = f"{ws_base}/ws/discord_consolidation"
 
             logger.info(f"🌙 Triggering memory consolidation via WS (timeout={timeout}s)...")