Add macOS Ctrl keyboard shortcuts with terminal-aware overrides

Implement Linux-style Ctrl shortcuts (Ctrl+C/V/X/Z for clipboard, Ctrl+N/T/W
for navigation, etc.) while preserving terminal behavior where Ctrl+C sends
SIGINT. Uses per-app NSUserKeyEquivalents to remap Ghostty back to Cmd for
clipboard operations.

Also consolidate aerospace configuration by moving spans-displays preference
from system-level module to home-manager role, allowing full aerospace
configuration to live in home-manager for better modularity.

machines/johno-macbookpro/configuration.nix

@@ -1,10 +1,6 @@
 { config, lib, pkgs, ... }:
 
 {
-  imports = [
-    ../../modules/aerospace.nix
-  ];
-
   # Basic system configuration for macOS work laptop
   system.stateVersion = 6;
 
@@ -18,13 +14,6 @@
     NSGlobalDomain.AppleShowAllExtensions = true;
   };
 
-  # Enable our custom aerospace system configuration
-  # (separate from nix-darwin's services.aerospace which manages the service)
-  roles.aerospace = {
-    enable = true;
-    enableSpansDisplays = true;
-  };
-
   # TODO: Find a way to not duplicate this
   launchd.user.envVariables = {
     # DOOM Emacs environment variables