add slot ttl output with effective timeout config

agent/nix_builder_autoscaler/tests/test_reservations_api.py

@@ -111,6 +111,17 @@ def test_state_summary_returns_counts() -> None:
     assert body["slots"]["empty"] == 3
 
 
+def test_effective_config_returns_capacity_and_scheduler() -> None:
+    client, _, _, _ = _make_client()
+    response = client.get("/v1/config/effective")
+    assert response.status_code == 200
+    body = response.json()
+    assert body["capacity"]["max_slots"] == 8
+    assert body["capacity"]["idle_scale_down_seconds"] == 900
+    assert body["scheduler"]["tick_seconds"] == 3.0
+    assert body["scheduler"]["reconcile_seconds"] == 15.0
+
+
 def test_health_live_returns_ok() -> None:
     client, _, _, _ = _make_client()
     response = client.get("/health/live")