Improve persistence and reactor dynamics

tests/test_simulation.py

@@ -4,6 +4,7 @@ from pathlib import Path
 import pytest
 
 from reactor_sim import constants
+from reactor_sim.failures import HealthMonitor
 from reactor_sim.reactor import Reactor
 from reactor_sim.simulation import ReactorSimulation
 
@@ -13,7 +14,7 @@ def test_reactor_initial_state_is_cold():
     state = reactor.initial_state()
     assert state.core.fuel_temperature == constants.ENVIRONMENT_TEMPERATURE
     assert state.primary_loop.mass_flow_rate == 0.0
-    assert state.turbine.electrical_output_mw == 0.0
+    assert state.total_electrical_output() == 0.0
 
 
 def test_state_save_and_load_roundtrip(tmp_path: Path):
@@ -36,7 +37,18 @@ def test_health_monitor_flags_core_failure():
     reactor = Reactor.default()
     state = reactor.initial_state()
     state.core.fuel_temperature = constants.MAX_CORE_TEMPERATURE
-    failures = reactor.health_monitor.evaluate(state, True, True, True, dt=200.0)
+    failures = reactor.health_monitor.evaluate(state, True, True, [True, True, True], dt=200.0)
     assert "core" in failures
     reactor._handle_failure("core")
     assert reactor.shutdown is True
+
+
+def test_maintenance_recovers_component_health():
+    monitor = HealthMonitor()
+    pump = monitor.component("secondary_pump")
+    pump.integrity = 0.3
+    pump.fail()
+    restored = monitor.maintain("secondary_pump", amount=0.5)
+    assert restored is True
+    assert pump.integrity == pytest.approx(0.8)
+    assert pump.failed is False