Run Windows training agent without console

tools/windows_training_agent.py

@@ -296,7 +296,11 @@ def log(path: Path, message: str) -> None:
     path.parent.mkdir(parents=True, exist_ok=True)
     stamp = datetime.now().astimezone().isoformat(timespec="seconds")
     line = f"[{stamp}] {message}"
-    print(line, flush=True)
+    if sys.stdout is not None:
+        try:
+            print(line, flush=True)
+        except OSError:
+            pass
     with path.open("a", encoding="utf-8") as handle:
         handle.write(line + "\n")