refactor: remove unnecessary single-element loop in disk usage calc

The 'for pattern in [f"hermes-*{task_id[:8]}*"]' was a loop over a
single-element list — just use a plain variable instead.

tools/terminal_tool.py

@@ -638,12 +638,11 @@ def get_active_environments_info() -> Dict[str, Any]:
         "workdirs": {},
     }
     
-    # Calculate total disk usage
+    # Calculate total disk usage (per-task to avoid double-counting)
     total_size = 0
     for task_id in _active_environments.keys():
-        # Check sandbox and workdir sizes
         scratch_dir = _get_scratch_dir()
-        for pattern in [f"hermes-*{task_id[:8]}*"]:
+        pattern = f"hermes-*{task_id[:8]}*"
         import glob
         for path in glob.glob(str(scratch_dir / pattern)):
             try: