Add Super + Ctrl + Alt + F to toggle a full screen desktop (#10672)

Hiding the top bar and removing the window gaps are the two things you
do to give the screen entirely to your windows, and doing both took two
hands and two hotkeys. `omarchy toggle fullscreen desktop` does them
together.

It only leaves full screen when both halves are in it, so hitting the
hotkey with just the bar hidden (or just the gaps gone) pulls the other
half into line instead of flipping the one you already set.


Claude-Session: https://claude.ai/code/session_01JB9phxP56gnP7qSidkkUJE

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

manual/07-hotkeys.md

@@ -192,6 +192,7 @@ All style options are also accessible under _Style_ in the Omarchy menu (`Super
 | `Shift + Mute` | Switch to next audio output |
 | `Shift + Play` | Switch to next media source |
 | `Super + Shift + Backspace` | Toggle window gaps |
+| `Super + Ctrl + Alt + F` | Toggle full screen desktop (top bar + window gaps) |
 
 ## Reminders