feat: define action completion costs

tests/action_system_boundaries_test.gd

@@ -82,6 +82,15 @@ func _test_selection_and_execution_are_separate() -> void:
 		unfunded_selection.action_id == SimulationIds.ACTION_GATHER_WOOD,
 		"A guard should gather wood instead of selecting patrol when its material cost is unavailable"
 	)
+	_check(
+		(
+			unfunded_selection.rejections.has(SimulationIds.ACTION_PATROL)
+			and "Needs 1 Wood" in String(
+				unfunded_selection.rejections[SimulationIds.ACTION_PATROL]
+			)
+		),
+		"Selection should expose a readable definition-backed rejection reason"
+	)
 
 
 func _test_target_resolution_and_travel_are_separate() -> void:

tests/food_storage_loop_test.gd

@@ -204,6 +204,16 @@ func _test_wood_work_requires_material() -> void:
 		),
 		"Patrol should not consume partial wood or create safety when its full cost cannot be paid"
 	)
+	var blocked_events: Array[EconomicEventRecord] = manager.get_npc_events(npc.id, 2)
+	_check(
+		(
+			not blocked_events.is_empty()
+			and StringName(blocked_events[0].data["event_type"])
+			== SimulationIds.EVENT_TASK_BLOCKED
+			and "needs 1 Wood" in String(blocked_events[0].data.get("action_name", ""))
+		),
+		"An unpaid completion cost should create a readable blocked-task fact"
+	)
 
 	manager.add_wood(1.5)
 	_check(

tests/npc_visual_lifecycle_test.gd

@@ -63,7 +63,8 @@ func _run() -> void:
 		SimulationIds.ACTION_GATHER_FOOD,
 		-1.0,
 		"Test shortage reason",
-		{SimulationIds.ACTION_GATHER_FOOD: 4.5}
+		{SimulationIds.ACTION_GATHER_FOOD: 4.5, SimulationIds.ACTION_PATROL: -1000000.0},
+		{SimulationIds.ACTION_PATROL: "Needs 1 Wood (0.5 available)"}
 	)
 	manager.latest_decisions[npc.id] = test_decision
 	manager.emit_signal("npc_decision_recorded", npc, test_decision)
@@ -75,6 +76,14 @@ func _run() -> void:
 		and npc.npc_name in inspector_label.text,
 		"NPC inspector should show the selected villager's real decision reason"
 	)
+	_check(
+		(
+			"Unavailable" in inspector_label.text
+			and "Patrol — Needs 1 Wood" in inspector_label.text
+			and "-1000000" not in inspector_label.text
+		),
+		"NPC inspector should explain rejected actions without sentinel utility scores"
+	)
 	var carried_food: MeshInstance3D = visual.get_node("CarriedFood")
 	_check(not carried_food.visible, "NPC should begin without a carried-food prop")
 	npc.add_inventory(SimulationIds.RESOURCE_FOOD, 1.0)

tests/simulation_definitions_test.gd

@@ -65,6 +65,22 @@ func _test_definition_backed_behavior() -> void:
 		study.preferred_profession_id == SimulationIds.PROFESSION_SCHOLAR,
 		"Study should reference the stable scholar profession ID"
 	)
+	_check(
+		(
+			study.completion_cost_resource_id == SimulationIds.RESOURCE_WOOD
+			and is_equal_approx(study.completion_cost_amount, 1.0)
+			and study.has_completion_cost()
+		),
+		"Study should declare its completion cost through definition metadata"
+	)
+	var patrol := SimulationDefinitions.get_action(SimulationIds.ACTION_PATROL)
+	_check(
+		(
+			patrol.completion_cost_resource_id == SimulationIds.RESOURCE_WOOD
+			and is_equal_approx(patrol.completion_cost_amount, 1.0)
+		),
+		"Patrol should share the proven one-wood completion-cost contract"
+	)
 	var gather := SimulationDefinitions.get_action(SimulationIds.ACTION_GATHER_FOOD)
 	_check(
 		(