launchd: add agent domain option

Allow Darwin LaunchAgents to target either the GUI or user launchd domain while preserving gui as the compatibility default.

tests/modules/launchd/agent-domain.nix

@@ -0,0 +1,20 @@
+{
+  config = {
+    launchd.agents."user-service" = {
+      enable = true;
+      domain = "user";
+      config.ProgramArguments = [
+        "/some/command"
+      ];
+    };
+
+    nmt.script = ''
+      serviceFile=LaunchAgents/org.nix-community.home.user-service.plist
+      assertFileExists $serviceFile
+
+      domainFile=LaunchAgentDomains/org.nix-community.home.user-service.domain
+      assertFileExists $domainFile
+      assertFileContent $domainFile ${builtins.toFile "expected-domain" "user\n"}
+    '';
+  };
+}

tests/modules/launchd/agents.nix

@@ -22,6 +22,16 @@
       serviceFile=LaunchAgents/org.nix-community.home.test-service.plist
       assertFileExists $serviceFile
       assertFileContent $serviceFile ${./expected-agent.plist}
+
+      domainFile=LaunchAgentDomains/org.nix-community.home.test-service.domain
+      assertFileExists $domainFile
+      assertFileContent $domainFile ${builtins.toFile "expected-domain" "gui\n"}
+
+      assertFileExists activate
+      assertFileContains activate 'readAgentDomain'
+      assertFileContains activate 'resolveDomain'
+      assertFileContains activate "printf 'gui/%s"
+      assertFileContains activate "printf 'user/%s"
     '';
   };
 }

tests/modules/launchd/default.nix

@@ -1 +1,4 @@
-{ launchd-agents = ./agents.nix; }
+{
+  launchd-agent-domain = ./agent-domain.nix;
+  launchd-agents = ./agents.nix;
+}