feat: spawn enemies from reusable definitions

tests/content_catalog_test.gd

@@ -51,7 +51,7 @@ func _test_core_pack() -> void:
 		"Core items should include food, wood, sword, and claw in stable-ID order"
 	)
 	_check(
-		_enemy_ids(catalog.get_enemies()) == [&"enemy_raider", &"enemy_wolf"],
+		_enemy_ids(catalog.get_enemies()) == [&"enemy_boar", &"enemy_raider", &"enemy_wolf"],
 		"Core enemies should enumerate by stable ID"
 	)
 	var food := catalog.get_item(SimulationIds.RESOURCE_FOOD)
@@ -69,10 +69,15 @@ func _test_core_pack() -> void:
 		"Claw should preserve its weapon contract"
 	)
 	var wolf := catalog.get_enemy(&"enemy_wolf")
+	var boar := catalog.get_enemy(&"enemy_boar")
 	_check(
 		wolf != null and wolf.weapon_id == SimulationIds.ITEM_CLAW,
 		"Enemy references should resolve against catalog items"
 	)
+	_check(
+		boar != null and boar.behavior_profile_id == wolf.behavior_profile_id,
+		"New enemy types should be able to reuse an existing behavior profile"
+	)
 
 
 func _test_deterministic_enumeration_and_dependencies() -> void: