fix(signals): suspend uninitialized async across lanes

[javascript-unsafe]

Fixes #3276.

An uninitialized async source has no committed stale value to show. Suspend it even when the reader is running under a different optimistic lane, so a latest()-conditioned branch keeps its existing DOM until the source resolves.

Adds a DOM regression test covering latest(entangle) ? asyncValue() : ....

Tests:

• pnpm exec vitest run test/latest-conditional-async-issue-3276.spec.tsx test/latest-async.spec.tsx test/latest-banner-landing-gap.spec.tsx test/latest-ispending-issue-3041.spec.tsx test/ispending-gated-landing.spec.tsx test/loading.spec.tsx test/dev-warning.spec.tsx
• JSX_COMPILER=babel pnpm exec vitest run test/latest-conditional-async-issue-3276.spec.tsx

[changeset-bot]

🦋 Changeset detected

Latest commit: 2512a43

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

This PR includes changesets to release 11 packages

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

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[codspeed-hq]

Merging this PR will not alter performance

✅ 136 untouched benchmarks

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_{Comparing javascript-unsafe:fix/latest-conditional-async-gate-3276 (2512a43) with next (4850a00)}

[ryansolid]

Follow-up note: this merged while I was preparing a size-relocated variant, so the relocation landed as fa568d3 on top — same semantics, but the uninitialized check now lives in laneSuspends (optimistic module) instead of core read()'s throw path. The inline placement taxed every bundle including storeless floors (27-66 B across five size scenarios, which is why the Size check on this PR was red); laneSuspends is only reachable under a lane, which implies the engine is installed, so only bundles that retain the optimistic module pay (~8 B on isPending/latest). Your test is on next unchanged and green. Thanks again — sharp diagnosis and exactly the right contract.