Hide empty server slots (0.0.0.0) from list_servers output

Only show servers with actual IP addresses. Empty slots are
HAProxy pre-allocated placeholders that add noise to the output.

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

haproxy_mcp/tools/servers.py

@@ -73,9 +73,12 @@ def _haproxy_list_servers_impl(domain: str) -> str:
         for server_name, srv_info in backend_servers.items():
             addr = srv_info["addr"]
             port = srv_info["port"]
-            status = "active" if addr != "0.0.0.0" else "disabled"
-            servers.append(f"• {server_name}: {addr}:{port} ({status})")
+            if addr == "0.0.0.0":
+                continue
+            servers.append(f"• {server_name}: {addr}:{port}")
 
+        if not servers:
+            return f"No active servers for {domain} ({backend})"
         return f"Servers for {domain} ({backend}):\n" + "\n".join(servers)
     except (HaproxyError, ValueError) as e:
         return f"Error: {e}"