refactor(agent): capture subagent runtime before spawn

tests/agent/test_loop_runner_integration.py

@@ -9,7 +9,8 @@ import pytest
 
 from nanobot.bus.outbound_events import StreamedResponseEvent
 from nanobot.config.schema import AgentDefaults
-from nanobot.providers.base import LLMResponse, ToolCallRequest
+from nanobot.providers.base import GenerationSettings, LLMResponse, ToolCallRequest
+from nanobot.utils.llm_runtime import LLMRuntime
 
 _MAX_TOOL_RESULT_CHARS = AgentDefaults().max_tool_result_chars
 
@@ -21,6 +22,7 @@ def _make_loop(tmp_path):
     bus = MessageBus()
     provider = MagicMock()
     provider.get_default_model.return_value = "test-model"
+    provider.generation = GenerationSettings()
 
     with patch("nanobot.agent.loop.ContextBuilder"), \
          patch("nanobot.agent.loop.SessionManager"), \
@@ -316,7 +318,6 @@ async def test_subagent_max_iterations_announces_existing_fallback(tmp_path, mon
         tool_calls=[ToolCallRequest(id="call_1", name="list_dir", arguments={"path": "."})],
     ))
     mgr = SubagentManager(
-        provider=provider,
         workspace=tmp_path,
         bus=bus,
         max_tool_result_chars=_MAX_TOOL_RESULT_CHARS,
@@ -329,7 +330,14 @@ async def test_subagent_max_iterations_announces_existing_fallback(tmp_path, mon
     monkeypatch.setattr("nanobot.agent.tools.filesystem.ListDirTool.execute", fake_execute)
 
     status = SubagentStatus(task_id="sub-1", label="label", task_description="do task", started_at=time.monotonic())
-    await mgr._run_subagent("sub-1", "do task", "label", {"channel": "test", "chat_id": "c1"}, status)
+    await mgr._run_subagent(
+        "sub-1",
+        "do task",
+        "label",
+        {"channel": "test", "chat_id": "c1"},
+        status,
+        LLMRuntime.capture(provider, "test-model", context_window_tokens=128_000),
+    )
 
     mgr._announce_result.assert_awaited_once()
     args = mgr._announce_result.await_args.args