feat(scala): m09 input/app/runtime and m10 extensions with tests

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scala/test/M09Helpers.test.scala

@@ -0,0 +1,11 @@
+package snake
+
+/** Test helpers shared by the m09 suites. */
+object M09Helpers:
+
+  /** The m09 program built from classicActions (ticks every 150 ms). The shipped `main` switches to speedActions in m10. */
+  lazy val classicMain: IO[Stream[IO[Unit]]] =
+    IO.randomSeed.map(seed => App.states(seed, App.classicActions).map(App.render))
+
+  /** The shapes an IO draws, in order (interpreted by `IO.trace`). */
+  def drawn(io: IO[Unit]): List[Shape] = IO.trace(io, 0).ops.collect { case Op.Draw(shape) => shape }