fix: track nested deep optimistic store pending state

[brenelz]

Fixes #2718

Fix: Nested deep(optimisticStore) Pending State

Problem

isPending(() => deep(optimisticStore)) stayed false during an optimistic transition when the optimistic write happened inside a nested object or array.

Example:

setStore(s => {
  s.items[0].name = "Modified";
});

In this case, the optimistic value was visible immediately, but isPending(() => deep(store)) did not become true until a later refresh().

Root Cause

deep() uses snapshotImpl() to recursively traverse a store and subscribe to every nested store node.

When snapshotImpl() found a store proxy, it reset the proxy lookup map to the global store lookup:

lookup = storeLookup;

That works for regular stores, but optimistic stores use their own STORE_LOOKUP map for nested proxies.

Because the traversal switched back to the global lookup, nested optimistic objects could be traversed as plain data instead of through their optimistic store proxies. As a result, isPending() did not collect the nested pending source.

Fix

Preserve the current store's lookup map when one exists:

lookup = target[STORE_LOOKUP] ?? storeLookup;

This keeps nested traversal inside the optimistic store's proxy graph, allowing deep() to read the nested optimistic nodes and allowing isPending() to observe their pending state immediately.

[changeset-bot]

🦋 Changeset detected

Latest commit: e17633c

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 9 packages

Name	Type
@solidjs/signals	Patch
test-integration	Patch
solid-js	Patch
babel-preset-solid	Patch
@solidjs/web	Patch
@solidjs/html	Patch
@solidjs/h	Patch
@solidjs/universal	Patch
@solidjs/element	Patch

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[codspeed-hq]

Merging this PR will not alter performance

✅ 118 untouched benchmarks

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_{Comparing brenelz:fix-nested-deep-optimistic-pending (e17633c) with next (f083220)}