clanCore: Fixed missing type null for clanIcon

nixosModules/clanCore/flake-module.nix

@@ -33,7 +33,7 @@
         '';
       };
       clanIcon = lib.mkOption {
-        type = lib.types.path;
+        type = lib.types.either lib.types.path lib.types.null;
         description = ''
           the location of the clan icon
         '';

pkgs/clan-cli/clan_cli/nix.py

@@ -82,6 +82,7 @@ def nix_eval(flags: list[str]) -> list[str]:
     return default_flags + flags
 
 
+@deal.raises(ClanError)
 def nix_metadata(flake: str) -> dict[str, Any]:
     cmd = nix_command(["flake", "metadata", "--json", flake])
     proc = subprocess.run(cmd, check=True, text=True, stdout=subprocess.PIPE)