[Windows] computer-use still uses EnumWindows although EnumDesktopWindows works in sandbox

Summary

On Windows, OpenDesktopW("Default", 0, FALSE, DESKTOP_READOBJECTS) plus EnumDesktopWindows works in the sandbox, but bundled @oai/sky window/app listing still fails.

Reproduction

sky.list_windows() and sky.list_apps() both return:

EnumWindows failed: The system cannot find the path specified. (0x80070003)

Independent control test: OpenDesktopW succeeds; EnumDesktopWindows succeeds; 464 windows are enumerated; GetWindowThreadProcessId/GetWindowTextW and CloseDesktop succeed; no desktop switch is performed.

Expected behavior

sky.list_windows() and sky.list_apps() should work when the process can open WinSta0\\Default for read access.

Suspected cause

The native Windows implementation still relies on EnumWindows, which does not see the relevant windows from this sandbox desktop context. The verified compatible path is OpenDesktopW plus EnumDesktopWindows.

Proposed fix

Under the Computer Use native Windows implementation (suspected area: project/cua/sky_js/plugin): open Default with OpenDesktopW; enumerate with EnumDesktopWindows; keep existing HWND metadata APIs; always call CloseDesktop; preserve a clear denial/error path; do not switch desktops.

Acceptance criteria

• list_windows returns windows and metadata.
• list_apps succeeds.
• No interactive desktop switch is required.
• Desktop handles close on success and failure.
• Existing behavior remains unchanged when OpenDesktopW is unavailable.

Notes

No custom binary or IPC wrapper was used.