Restructure modules/shared and update all imports

- Delete 2024-12-rework/ folder
- Rename modules/hosts/common to modules/shared, then split into:
  - modules/shared/home/general
  - modules/shared/home/linux
  - modules/shared/nixos
- Update all import paths throughout the codebase
- Update lib/*.nix to use new paths
- Fix hardcoded /Users/${username} to use config.home.homeDirectory
- Update README and examples/flake-structure.nix

flake.nix

@@ -87,28 +87,6 @@
     # Functions that setup systems
     localLib = import ./lib { inherit inputs; };    
 
-    linuxHomeConfig = { system, hostname, username, additionalModules, additionalSpecialArgs }: inputs.home-manager.lib.homeManagerConfiguration {
-      extraSpecialArgs = { inherit inputs hostname username;
-        pkgs = import inputs.nixpkgs {
-          inherit system;
-          config = {
-            allowUnfree = true;
-            permittedInsecurePackages = [ "olm-3.2.16" "electron-21.4.4" ];
-          };
-        };
-      } // additionalSpecialArgs;
-      modules = [
-        ./modules/home-manager/hosts/${hostname}/${username}.nix
-        {
-          home = {
-            username = "${username}";
-            homeDirectory = "/home/${username}";
-          };
-        }
-        inputs.sops-nix.homeManagerModules.sops
-      ] ++ additionalModules;
-    }; # end homeManagerConfiguration
-
   in {
     # Darwin (macOS) hosts
     darwinConfigurations = {