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.

simulation/SimulationManager.gd

@@ -15,6 +15,7 @@ var village := SimVillage.new()
 var npcs: Array[SimNPC] = []
 @export var tick_interval := 1.2
 @export var simulation_seed: int = 1337
+@export var cycle_duration_seconds := 240.0
 @export var debug_logs := true
 @export var active_world_adapter: Node
 
@@ -42,6 +43,7 @@ func _ready() -> void:
 		set_process(false)
 		return
 	clock = SimulationClock.new(tick_interval)
+	clock.cycle_duration_seconds = cycle_duration_seconds
 	village.debug_logs = debug_logs
 	_initialize_storage()
 	village.update_modifiers()
@@ -112,7 +114,7 @@ func simulate_tick() -> void:
 			and old_state in [SimNPC.TASK_STATE_IDLE, SimNPC.TASK_STATE_COMPLETE]
 			and npc.task_state in [SimNPC.TASK_STATE_IDLE, SimNPC.TASK_STATE_COMPLETE]
 		):
-			var selection := action_selector.select_action(npc, village)
+			var selection := action_selector.select_action(npc, village, clock.time_of_day())
 			if selection != null:
 				latest_decisions[npc.id] = selection
 				npc_decision_recorded.emit(npc, selection)
@@ -195,6 +197,11 @@ func simulate_tick() -> void:
 				withdraw_to_npc(npc, SimulationIds.RESOURCE_FOOD, 1.0)
 			elif completed_task == SimulationIds.ACTION_EAT:
 				consume_npc_food(npc)
+			elif completed_task == SimulationIds.ACTION_SLEEP:
+				npc.energy = minf(npc.energy + 40.0, 100.0)
+				npc.position = npc.home_position
+				if debug_logs:
+					print("[SimulationManager] ", npc.npc_name, " completed sleep at home")
 			elif (
 				completed_task
 				not in [SimulationIds.ACTION_GATHER_FOOD, SimulationIds.ACTION_GATHER_WOOD]
@@ -354,14 +361,19 @@ func notify_npc_target_unavailable(npc_id: int) -> void:
 
 
 func resolve_npc_target(npc_id: int, origin: Vector3) -> bool:
-	if active_world_adapter == null:
-		push_error("SimulationManager: active_world_adapter is missing")
-		return false
 	for npc in npcs:
 		if npc.id != npc_id:
 			continue
 		if npc.is_dead or npc.task_state != SimNPC.TASK_STATE_TRAVELING:
 			return false
+		if npc.current_task == SimulationIds.ACTION_SLEEP:
+			npc.travel_target_position = npc.home_position
+			npc.has_travel_target = true
+			npc_travel_requested.emit(npc, npc.travel_target_position)
+			return true
+		if active_world_adapter == null:
+			push_error("SimulationManager: active_world_adapter is missing")
+			return false
 		var result := target_resolver.resolve(npc, origin, self, active_world_adapter)
 		if result.is_empty():
 			notify_npc_target_unavailable(npc.id)
@@ -738,7 +750,8 @@ func create_state_record() -> SimulationStateRecord:
 		"clock_accumulator": clock.accumulator,
 		"clock_elapsed_ticks": clock.elapsed_ticks,
 		"wander_random_streams": wander_streams,
-		"next_event_id": next_event_id
+		"next_event_id": next_event_id,
+		"cycle_duration_seconds": clock.cycle_duration_seconds
 	}
 	record.village = VillageStateRecord.capture(village)
 	for npc in npcs:
@@ -782,6 +795,7 @@ func restore_state(record: SimulationStateRecord) -> bool:
 	clock = SimulationClock.new(tick_interval)
 	clock.accumulator = float(record.simulation["clock_accumulator"])
 	clock.elapsed_ticks = int(record.simulation["clock_elapsed_ticks"])
+	clock.cycle_duration_seconds = float(record.simulation.get("cycle_duration_seconds", 240.0))
 	village = record.village.restore(debug_logs)
 	storage_states.clear()
 	for storage_record in record.storages: