feat: add NPC schedules with sleep, meal, and work periods

Add ACTION_SLEEP with home-position targeting and energy restoration. Embed schedule periods (SLEEP/MEAL/WORK/DISCRETIONARY) in ActionSelectionSystem with TimeOfDay from SimulationClock. NPCs sleep at night when energy is low, eat during meal periods when hungry, and work/discretionary the rest of the cycle. Home position stored per NPC and serialized through NPCStateRecord with backward-compatible fallback. Cycle duration persisted through save/restore. Includes headless test for sleep period, work period, meal hunger, energy restoration, serialization round-trip, and home targeting without world adapter.

tests/food_storage_loop_test.gd

@@ -12,6 +12,7 @@ func _run() -> void:
 	manager.debug_logs = false
 	root.add_child(manager)
 	manager.set_process(false)
+	manager.clock.elapsed_ticks = 100
 
 	var pantry: StorageStateRecord = manager.get_pantry()
 	pantry.withdraw(SimulationIds.RESOURCE_FOOD, 1000.0)