Add architecture package and application skeleton

tests/unit/test_graph.py

@@ -0,0 +1,21 @@
+from ai_orchestrator.domain.enums import NodeStatus, NodeType
+from ai_orchestrator.domain.models import ExecutionGraph, ExecutionNode
+
+
+def test_graph_marks_pending_node_ready_when_dependencies_are_completed() -> None:
+    first = ExecutionNode(task_id="task_1", node_type=NodeType.PLANNER, input_data={})
+    second = ExecutionNode(
+        task_id="task_1",
+        node_type=NodeType.FINALIZER,
+        input_data={},
+        dependencies=[first.node_id],
+    )
+    first.mark_completed({"ok": True})
+    graph = ExecutionGraph(task_id="task_1", nodes=[first, second])
+
+    ready = graph.ready_nodes()
+
+    assert len(ready) == 1
+    assert ready[0].node_id == second.node_id
+    assert second.status == NodeStatus.READY
+