Fix aerospace namespace conflict and claude-code override

Rename custom aerospace module from services.aerospace to roles.aerospace
to avoid conflicting with nix-darwin's built-in aerospace service support.

Move claude-code package override to flake-level overlay to ensure the
GCS-distributed version is used instead of the npm registry version in
unstable. This is necessary for corporate environments where npm registry
access may be blocked.

flake.nix

@@ -110,6 +110,13 @@
             unstable = import nixpkgs-unstable {
               system = prev.system;
               config.allowUnfree = true;
+              overlays = [
+                # Override claude-code in unstable to use our custom GCS-based build
+                # (needed for corporate networks that block npm registry)
+                (ufinal: uprev: {
+                  claude-code = prev.custom.claude-code or (prev.callPackage ./packages {}).claude-code;
+                })
+              ];
             };
             custom = prev.callPackage ./packages {};
             # Compatibility: bitwarden renamed to bitwarden-desktop in unstable