[Bug] Screen Locked Bypass

## Environment
Windows 10 machine

## Reproduction
- Screen is locked
- Press the `Alt-key`
- Press `Alt-F` (default search hotkey)
- Press `Esc`
- Screen is still locked, but you are now focused on the terminal in the background and can type any command

Instead of pressing `Alt-F`, one can also press the `Down-Arrow-Key` to access the context menu, allowing you to arbitrarily open new terminals.

## Suggested Fix
Disable `Alt` commands when locked.

No source file or test is named. Start by locating the Windows screen-lock handling and the keyboard paths for Alt-F and the Down Arrow/context menu. Done means those commands cannot reach or open terminals while the screen is locked, and the reported reproduction no longer exposes the background terminal.

Written by the indexing model from the issue text.