21efeb51bb
teknium1 noticed execute_code was missing from his enabled tools on Windows. Root cause: tools/code_execution_tool.py set ``SANDBOX_AVAILABLE = sys.platform != \"win32\"`` as a module-level constant, originally because the RPC transport required AF_UNIX. We added loopback TCP fallback for the sandbox in commit eeb723fff (and covered it in the Windows TCP tests), but forgot to lift the availability gate. So execute_code was still invisible via the check_fn path on Windows. - SANDBOX_AVAILABLE is now True unconditionally (it's still checked — a future platform could flip it off via monkeypatch/env if needed). - Error message when disabled no longer mentions Windows specifically, just says 'sandbox is unavailable in this environment'. - test_windows_returns_error updated: patches SANDBOX_AVAILABLE=False directly (which was always its real intent) and asserts on 'unavailable' instead of 'Windows'. Tests: 171 code-execution + windows-compat tests pass, no regressions.