Refactor: Extract platform-specific roles to base-linux and base-darwin

Create base-linux and base-darwin modules to cleanly separate platform-
specific role imports from shared roles. This prevents importing modules
that require platform-specific home-manager modules (like plasma-manager
on NixOS) in environments where they don't exist (like nix-darwin).

- base-linux includes: plasma-manager, i3+sway
- base-darwin includes: aerospace
- roles/default.nix now only contains truly cross-platform roles

This architecture makes it immediately clear which roles are shared
versus platform-specific and makes it easy to add new platform-specific
roles in the future.

home/home-darwin-work.nix

@@ -1,30 +1,6 @@
 { config, lib, pkgs, globalInputs, system, ... }:
 
 {
-  # Claude Code Package Override for Corporate Work Environment
-  #
-  # This overlay overrides the default claude-code package specifically for work environments
-  # where corporate network restrictions may prevent access to npm registry distributions.
-  #
-  # Context:
-  # - The default claude-code package (used in home environments) fetches from npm registry
-  # - Corporate firewalls and security policies often block npm registry access
-  # - Our custom claude-code package uses Google Cloud Storage distribution as a workaround
-  # - This maintains the same package name across environments while adapting to network constraints
-  #
-  # Environment-specific behavior:
-  # - Home environments: Use standard npm-distributed claude-code package
-  # - Work environments: Use custom binary-distributed claude-code package from GCS
-  #
-  # This approach ensures consistent tooling availability regardless of network environment
-  # while respecting corporate security policies.
-  nixpkgs.overlays = [
-    (final: prev: {
-      unstable = prev.unstable // {
-        claude-code = prev.custom.claude-code;
-      };
-    })
-  ];
   # Home Manager configuration for Darwin work laptop
   # Corporate-friendly setup with essential development tools
 
@@ -140,5 +116,6 @@
 
   imports = [
     ./roles
+    ./roles/base-darwin
   ];
 }