Add architecture package and application skeleton

tests/unit/test_task_lifecycle.py

@@ -0,0 +1,15 @@
+from ai_orchestrator.domain.enums import TaskStatus
+from ai_orchestrator.domain.models import Task
+
+
+def test_task_status_transitions() -> None:
+    task = Task(project_id="default", goal="Test", inputs={})
+
+    task.mark_planned()
+    task.mark_running()
+    task.wait_for_confirmation("node_1")
+    task.complete({"result": "ok"})
+
+    assert task.status == TaskStatus.COMPLETED
+    assert task.current_node_id == "node_1"
+