fix(ui): stop the default-model picker spinning on every switch - #3828

Update on d5cb4e8b1b:

[P2] Optimistic pendingDefaultModel never clears on external Host change

pendingDefaultModel only clears when === selectedValue. If another window writes C after this window picked B, refresh updates selectedValue to C (B!=C) so pending B stays and keeps covering ModelPicker — Host authority is C but UI shows B or "unset" (stale/authority split).

Fix: bind optimistic to Host revision/target and discard on non-matching accepted refresh.

Checks on d5cb4e8b1bad49ae701f09fdcedc7b496ed65df5 are test: SUCCESS — code is NO-GO.

Update on c9c8cb311b:

[P2] Unconditional clear of optimistic leaves stale snapshot on refresh failure

GeneralDefaultsCard clears pendingDefaultModel after await onRefresh() even when reloadConnections swallowed getSnapshot failure or was invalidated without accepted snapshot. Host now holds B but picker reverts to old A with stale isVerified, allowing decisions from wrong default.

Fix: only clear on successful accepted snapshot; handle failure/invalidation.

Checks on c9c8cb311be7ebc75f4d255b1ac7bac1b6d933d4 are test: FAILURE — not green.

What this PR does: switching the default model in Settings › 通用 › 任务默认 › 默认模型 spun a spinner on the picker trigger for the whole save. ModelPicker drove the Astryx Selector through its async changeAction prop, whose built-in optimistic value holds the trigger aria-busy until the controlled value catches up — i.e. for the entire setDefaultModel + connection-refresh round trip. This switches ModelPicker to the synchronous onChange path, matching the sibling permission-mode and thinking-level selectors, and drops loading={saving} at the call site. It adds a Storybook regression story that pins a never-resolving save and asserts the trigger is not left aria-busy.

The spinner half is correct and the story is a real guard. But I read the installed Selector implementation and the trade it makes is the opposite of what the PR body describes, so I do not think this closes #3827 yet.

P2 — this removes the spinner by making the trigger label lag, which is the other half of the reported bug

packages/ui/src/model-picker.tsx:100, apps/desktop/src/renderer/settings/general-settings-page.tsx:659

Reachability ①, every switch.

In node_modules/@astryxdesign/core/dist/Selector/Selector.js:

const commitValue = useCallback(newValue => {
  onChange?.(newValue);
  if (changeAction) {
    startTransition(async () => {
      setOptimisticValue(newValue);
      await changeAction(newValue);
    });
  }
}, [...]);

setOptimisticValue runs only on the changeAction branch. The trigger's label comes from valueContent, which renders selectedItem, which is selectableItems.findIndex(item => item.value === optimisticValue). And the Spinner is rendered as a sibling of valueContent, not in place of it.

So the actual before/after is:

disabled={saving} is kept, so during that window the row shows the old model on a disabled trigger — on a slow Runtime Host round trip the pick reads as if it did not take.

#3827 asks for both: "selecting a model reflects the choice immediately with no spinner". This PR delivers the second and gives up the first.

The PR body says it "reflects the pick optimistically in the Settings row so the label updates instantly instead of waiting for the refresh" — that change is not in the diff. general-settings-page.tsx only loses the loading={saving} line; value={selectedValue} is still derived purely from props.defaultSlug / props.connections. Did an earlier revision carry it?

The fix is small and is exactly what the body already promises: a local pending value in GeneralDefaultsCard, preferred over selectedValue while saving, cleared when the refresh lands or the save fails.

Note the new story cannot catch this: it pins value fixed and asserts only not aria-busy, so it stays green whether or not the label ever updates.

Ungraded

ModelPicker has exactly one production consumer (this Settings row) — nothing else in apps or packages renders it. With loading={saving} gone, the loading → isLoading path now has no production caller, while the new comment says "spinning is opt-in via the explicit loading prop". Either keep it and say it is currently unused, or drop the prop.

AI use: Claude Code assisted with reading the installed Astryx Selector implementation; the verification and conclusions are my own.