perf: harden runtime for weaker hardware

tests/animal_routine_vertical_slice_test.gd

@@ -130,6 +130,10 @@ func _run() -> void:
 	)
 	var reloaded_goat := load("res://world/animals/goat/cozy_goat.tscn").instantiate() as AnimalNode
 	animals_parent.add_child(reloaded_goat)
+	# Freeze presentation movement while proving that binding itself is a pure
+	# reload. A physics step may otherwise land between add_child() and the next
+	# process frame and legitimately advance the authoritative route.
+	reloaded_goat.set_physics_process(false)
 	await process_frame
 	goat = reloaded_goat
 	goat.move_speed = 4.0
@@ -141,6 +145,7 @@ func _run() -> void:
 		),
 		"Reloading the self-contained goat scene should bind the same state without resetting it"
 	)
+	goat.set_physics_process(true)
 	for _frame in 3:
 		await physics_frame
 	_check(