One module owns the document keydown listener and dispatches the shortcut map
(Cmd/Ctrl+Shift+N / +K / +S / +, / Escape), platform-aware, via the single-source
focus-utils interactive-context gate. Escape and Cmd/Ctrl+S run before the gate so
save works while editing; the rest are suppressed mid-typing. Publish + its toast
move into services/snippet-actions so the button and Cmd/Ctrl+S behave identically.
Removes the ad-hoc keydown handler from App and Monaco's Cmd+S command.