A test that waits for a deadline somebody guessed is waiting for the wrong thing, so it waits for the editor (#93)

The suite spent 88% of its step time asleep: 564 s of steps, 496 s of
them in sleep(n) - fixed spans estimated by hand and then copied from
step to step. That is why it was slow, and why it flickered.

The signal is afterFrames(count, timeout) in ui/render.ts, exposed as
__gm.afterFrames(). It wakes the loop itself, because an editor that
draws nothing would never redeem a promise of a frame, and it gives up
after a timeout instead of hanging the run. settle() in the harness
waits two drawn frames (~32 ms) instead of 150-300 ms and falls back to
sleep(150) when the hook is missing (an old build): silently not
waiting would make every later check a coin toss.

Every action goes through it now - click, doubleClick, wheel, drag,
dragAsset, press, typeText, select, mutate, undo, redo - and with that
about 550 sleep() calls behind those actions became redundant, helpers
that are nothing but a mutate in a coat included. What a frame cannot
answer got its own condition instead: waitUntil(expr), play()/stop()
waiting on __gm.state.mode rather than on 300 ms, saved() for the
autosave (the two hand-written polling loops sampled at 300 ms for
something that arrives after a second), and showTab() as a real tool -
47 places called evaluate("__gm.showTab(...)") raw, and 24 of them
waited for nothing at all and read the old panel.

564 s -> 243 s of step time, the waiting share 88% -> 76%. Three kinds
of wait were kept, and each one bit when it was taken away: loading
bytes (textures, fonts), game time that a repaint cannot stand in for
(time scale, shader and particle clocks, the live values a running
graph carries), and the inertia the scroll step measures on purpose.

Two things the new speed uncovered, both real: 25-animation read the
frame menu unfiltered and had frozen an incomplete list (the CI failure
on c990dbc), and 33-render-on-change measured idleness while the
autosave of the step before was still painting - it waits for
saveStatus to leave dirty/saving now, so it measures that nothing
happens any more instead of that it waited long enough.

tools/e2e/10-text-and-enabled.mjs

@@ -2,7 +2,6 @@
 export async function textAndEnabled(t) {
   const {
     check,
-    sleep,
     evaluate,
     json,
     has,
@@ -21,7 +20,6 @@ export async function textAndEnabled(t) {
   // 10a. Text assets: created through the + menu, placed, and rendered as real text in the scene.
   await clickText('+');
   await clickText('Text');
-  await sleep(100);
   const textAssetId = await evaluate(`(__gm.state.project.assets.find(a => a.type === 'text') || {}).id`);
   check('+ menu creates a text asset', Boolean(textAssetId));
   await mutate(`
@@ -31,7 +29,6 @@ export async function textAndEnabled(t) {
     const cam = __gm.state.activeScene.objects.find(o => o.id === 'o3').position;
     __gm.state.activeScene.objects.push({ id: 'otext', assetId: id, name: '', position: { x: cam.x, y: cam.y, z: 5 }, editorOffset: { x: 0, y: 0 }, overrides: {}, parentId: '', instanceEdits: {} });
     __gm.state.select({ kind: 'object', holderId: 'scene1', objectIds: ['otext'], objectId: 'otext' })`);
-  await sleep(100);
   check('a placed text object draws its content in the scene', await has('Hello world'));
   await shot('29-text-object');
 
@@ -44,7 +41,6 @@ export async function textAndEnabled(t) {
   const gizmoOn = await gizmoOf('otext');
   check('a selected object is framed at full strength', gizmoOn?.alpha === 1, JSON.stringify(gizmoOn));
   await click(enabledRow.x, enabledRow.y);
-  await sleep(100);
   const textObject = await object('otext');
   check(
     'clicking it writes an override instead of changing the asset',
@@ -75,11 +71,9 @@ export async function textAndEnabled(t) {
   );
   const otherRow = await evaluate(`__gm.hierarchyRow('o3')`);
   await click(otherRow.x, otherRow.y);
-  await sleep(100);
   check('selecting something else drops the frame', (await gizmoOf('otext')) === null);
   const offRow = await evaluate(`__gm.hierarchyRow('otext')`);
   await click(offRow.x, offRow.y);
-  await sleep(100);
   const gizmoBack = await gizmoOf('otext');
   check(
     'picking the switched-off object in the hierarchy frames it again',
@@ -92,10 +86,8 @@ export async function textAndEnabled(t) {
   // 10c. In the running game a switched-off object does not exist: it is not rendered, and
   //      switching it back on brings it back.
   await play();
-  await sleep(200);
   const offItems = (await json('__gm.gameInfo()')).visibleItems;
   await mutate(`__gm.state.activeScene.objects.find(o => o.id === 'otext').overrides.enabled = true`);
-  await sleep(200);
   const onItems = (await json('__gm.gameInfo()')).visibleItems;
   check(
     'the game renders one item more once the object is switched on',
@@ -112,7 +104,6 @@ export async function textAndEnabled(t) {
   await click(fontLabel.x + 160, fontLabel.y);
   await typeText('32.6');
   await press('Enter');
-  await sleep(200);
   const fontSize = (await object('otext')).overrides.fontSize;
   check('typing a fraction into it rounds the stored value', fontSize === 33, String(fontSize));
   check('and the field shows exactly what was stored', Boolean(await has('33')));