feat: player runtime for the Phone library and That New Teacher

Named stores (PyNamespace: dotted access, functions that see their own store first, restored after a
save is loaded), real generators run step by step (next, send, yield as an expression), len/bool through
__len__/__bool__, os/calendar/itertools/pygame_sdl2 helpers, Skip and ToggleLocalVariable actions,
text tags {glitch} and {wave} and plain display of explode/gradient/ruby, SnowBlossom and anim.Blink,
RoundedCorners as a transform, transforms listed in `at`, ATL choice weights that are flags, and
renpy.image_size from the converter's picture sizes.

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

frontend/tests/mist-runtime.test.mjs

@@ -8,6 +8,38 @@ const runtime = original ? JSON.parse(readFileSync(original, "utf8")) : null;
 const click = (element) => element.onclick({ stopPropagation() {}, preventDefault() {} });
 const enter = (engine, label) => engine.restart(() => engine.guardedJump(label));
 
+test("MIST's actual movie Skip survives a queued redraw and returns before its timer", { skip: !runtime }, async () => {
+  const { engine, root, window } = makeEngine(runtime);
+  globalThis.HTMLVideoElement = window.HTMLVideoElement ?? class {};
+  const played = [], stopped = [];
+  engine.audio.play = (...args) => played.push(args);
+  engine.audio.stop = (...args) => stopped.push(args);
+  engine.audio.mediaOf = () => null;
+  try {
+    engine.newStore();
+    Object.assign(engine.store, { movielength: 63, movieplaying: "images/animations/movies/Intro_Movie.webm" });
+    const completed = engine.exec({ op: "call_screen", name: "custommoviescreen", args: [], kw: {} });
+    const button = [...root.querySelectorAll(".pg-sbtn")].find((element) => element.textContent === "Skip");
+    assert.ok(button);
+    assert.equal(button.classList.contains("pg-sdisabled"), false);
+    engine.screens.refresh();
+    window.dispatchEvent(new window.Event("pointerdown"));
+    await until(() => engine.store.movielength < 63);
+    assert.equal(button.isConnected, true);
+    window.dispatchEvent(new window.Event("pointerup"));
+    click(button);
+    await completed;
+    assert.equal(engine.store._return, 0);
+    assert.ok(engine.store.movielength > 60, "Skip returns without waiting for the movie timer");
+    assert.equal(root.querySelector(".pg-sbtn"), null);
+    assert.equal(played[0][0], "movie");
+    assert.equal(stopped.at(-1)[0], "movie");
+  } finally {
+    window.dispatchEvent(new window.Event("pointercancel"));
+    engine.destroy();
+  }
+});
+
 test("MIST's actual raise-hand loop accepts screen input and resumes after a save", { skip: !runtime }, async () => {
   const { engine, root } = makeEngine(runtime);
   try {