fix: Refactor flake structure to properly use flake-parts

- Remove incorrect parts/fleet-data.nix import from flake.nix
- Create flake-parts wrappers for fleet-option.nix and users.nix
- Import inventory.nix through fleet-option wrapper
- Fix module argument passing (remove pkgs from mkFleet call)
- Move NixOS-specific modules out of flake-parts imports

This addresses the 'path does not exist' error but introduces infinite recursion that needs to be resolved.

parts/nixos-configurations.nix

@@ -1,12 +1,9 @@
 # NixOS configurations generated from fleet
-{ inputs, self, lib, pkgs, config, ... }:
+{ inputs, self, lib, config, ... }:
 {
-  imports = [
-    (import ../fleet/fleet-option.nix { inherit inputs lib pkgs config; })
-  ];
   flake.nixosConfigurations =
     let
-      fleet = self.lib.mkFleet { inherit inputs lib pkgs config; };
+      fleet = self.lib.mkFleet { inherit inputs lib config; };
     in
     fleet.nixosConfigurations;
 }