add agent(...) to the AgentWorkflowBuilder

Signed-off-by: Dmitrii Tikhomirov <chani.liet@gmail.com>

Author: treblereel

experimental/fluent/agentic/src/main/java/io/serverlessworkflow/fluent/agentic/AgentWorkflowBuilder.java

@@ -42,6 +42,17 @@ public static AgentWorkflowBuilder workflow(String name, String ns) {
     return new AgentWorkflowBuilder(name, ns, DEFAULT_VERSION);
   }
 
+  public AgentWorkflowBuilder agent(Object agent) {
+    return agent(UUID.randomUUID().toString(), agent);
+  }
+
+  public AgentWorkflowBuilder agent(String name, Object agent) {
+    final AgentDoTaskBuilder doTaskBuilder = this.newDo();
+    doTaskBuilder.agent(name, agent);
+    this.workflow.setDo(doTaskBuilder.build().getDo());
+    return this;
+  }
+
   public AgentWorkflowBuilder sequence(Object... agents) {
     return sequence(UUID.randomUUID().toString(), agents);
   }