Keep a driven video ready while its sprite is off (#404)

A cut between two videos flashed white: the sprite switched on had
no picture yet, because its player only opened then or had been
dropped meanwhile. A driven video now waits muted at its time while
its sprite is off, in the editor and in a run.

- A disabled sprite with Video clock Driven asks for its player
  without drawing it. A Free video still opens when shown.
- A run's draw list keeps disabled driven sprites, marked as off.
  Before, collectWorldItems dropped every disabled object, so the
  game view never held a player for them.
- VideoLibrary.wear() counts as asking. The sweeper dropped a held
  player after 2 to 4 s and it was loading again at the cut.
- The speed of the asked time is read over a window that grows to
  500 ms. Over 100 ms one 1/60 s step more or less read as 17 % off,
  the playback rate jumped and the sound dropped out.
- A stream feeds every packet it has loaded to the decoder at once
  and waits once. One round trip per 20 ms packet let the decoder
  fall behind on a busy main thread, which made e2e 34 flaky in CI.

Tests:
- Unit streaming, video-library, video-follow: green, 4 new
- e2e 34 + 66 (atx): ALL PASSED, stream skipped 0, 66m new
- e2e 66 (atx), two runs: ALL PASSED, 25 checks, 66n new
- Gate (atx): CHECK EXIT 0, 297 files, 4557 tests
- Counter-checks: without the draw list fix 66n finds no player,
  without the wear() fix and with the old speed reading the new
  unit tests turn red

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

tools/e2e/66-video.mjs

@@ -383,6 +383,49 @@ export async function video(t) {
   );
   await showTab('scene');
 
+  // 66m. Switched off, a driven sprite keeps its player ready at its Video time, longer than a player
+  //      nobody asks for lives: switched on, the first frame shows 1.2 s blue, not its plain colour.
+  //      4.5 s, as the sweeper looks only every 2 s and lets go of what is 2 s idle.
+  const switchLate = (on) =>
+    mutate(`
+      const late = __gm.state.activeScene.objects.find((o) => o.id === '${LATE}');
+      late.overrides = { ...late.overrides, videoTime: 1.2, enabled: ${on} };`);
+  await switchLate(false);
+  await sleep(4500);
+  const readied = (await json('__gm.videos()')).find((v) => v.key.includes(LATE));
+  await switchLate(true);
+  await t.evaluate('__gm.afterFrames(1)');
+  const firstShown = await colorAt(await json(`__gm.objectRect('${LATE}')`));
+  check(
+    'a driven sprite switched off keeps its video ready and shows its picture the frame it is switched on',
+    readied?.ready === true &&
+      readied.paused &&
+      readied.muted &&
+      Math.abs(readied.time - 1.2) < 0.05 &&
+      firstShown === COLORS.blue,
+    JSON.stringify({ readied, firstShown }),
+  );
+
+  // 66n. The same in a run: the world used to leave a switched-off object out of what the Game tab
+  //      draws, so a cut to it loaded the video only then and showed white meanwhile. Nor did wearing
+  //      the player count as asking for it: let go after 2 to 4 s, it was opened again.
+  await switchLate(false);
+  const sceneKeys = new Set((await json('__gm.videos()')).map((v) => v.key));
+  await play();
+  await sleep(4500);
+  const inRun = (await json('__gm.videos()')).filter((v) => v.key.includes(LATE) && !sceneKeys.has(v.key));
+  await stop();
+  await switchLate(true);
+  check(
+    'in a run, a driven sprite switched off keeps its video ready too',
+    inRun.length === 1 &&
+      inRun[0].ready &&
+      inRun[0].paused &&
+      inRun[0].muted &&
+      Math.abs(inRun[0].time - 1.2) < 0.05,
+    JSON.stringify(inRun),
+  );
+
   await mutate(`
     const p = __gm.state.project;
     const gone = ['${OBJECT}', '${EARLY}', '${LATE}'];