Command Palette: Allow global command shortcuts to act as a toggle (open and close)

### Description of the new feature / enhancement

Currently, when a user assigns a dedicated global hotkey to a specific command inside the Command Palette (for example, setting `Win + Shift + K` to open "Search App"), this hotkey only functions as a one-way trigger.

Pressing the hotkey opens the specific command window immediately. However, pressing the exact same hotkey again while the window is active does not close or hide it.

### Scenario when this would be used?

This would significantly improve workflow efficiency and muscle memory.
For instance, a user might quickly press `Win + Shift + K` to look up an app, change their mind, and want to press `Win + Shift + K` again to instantly dismiss it, without having to move their hand to reach for the `Esc` key or use the mouse to click away.

### Supporting information

- This behavior is standard across many productivity launchers (like Raycast, or even PowerToys' own global launcher shortcut).
- Currently, users have to manually press `Esc` to close it, which breaks the seamless experience of using custom-mapped global hotkeys for individual extensions or commands.

No file or test is named. Start by locating the Command Palette implementation that handles dedicated global command shortcuts, then trace how the palette opens and how Esc closes it. Done means pressing the same assigned shortcut while the command window is active hides it, while the existing open behavior remains intact.

Written by the indexing model from the issue text.