fix(signals): defer a transaction-owned node's committed children to its commit (#3404)

[brenelz]

Fixes #3404.

Bug

A render effect parked on a pending async source is stamped with the transaction by status propagation without being recomputed, so its owned children (nested render effects, memos, onCleanup registrations) still belong to the committed frame. When the source landed, recompute saw the _transition stamp and took the "dispose children immediately" branch, running their cleanups mid-hold. In the issue's repro a Portal under a keyed Show vanished when the first hop of an async chain landed and only reappeared once the whole chain settled, instead of swapping atomically.

Fix

• New CONFIG_HELD_CHILDREN bit: this node's current children were built by a pass whose result has not committed (a staged value, a pending window, a run under a held transaction).
• recompute disposes children immediately only for tracked effects or when the bit is set (no frame ever showed them). Everything else is deferred as zombies until the node's commit, whether or not a transaction owns the node.
• The bit is set at the tail of recompute whenever the pass's result waits on a commit, and cleared by commitPendingNode.
• Exception: a transaction-owned effect recomputed mainline (contested, 2.0.0-rc.7 render effect depending on non async values from two concurrent updates commit with the wrong data #3322) publishes its value directly, so that pass's children are the frame's and it releases its zombies itself rather than leaving two generations rendering until the transaction commits.

Tests

• packages/signals/tests/nested-render-effect-async-cleanup.test.ts: the issue's shape, a memo with onCleanup, a sync write during the hold (held children die silently, the frame's swap and then wait for the reveal), and the plain sync ordering pinned as it already was.
• packages/web/test/nested-render-effect-cleanup-issue-3404.spec.tsx: the Portal / Show / Loading scenario from the playground. Fails on next with an empty portal target mid-hold, passes with the fix.
• Full signals and web suites pass. Tree-shake floor +102 B, recorded in the budget ledger with the threshold raised accordingly.

Changeset and a note in INTERNALS-ASYNC-STATE.md included.

🤖 Generated with Claude Code

[changeset-bot]

🦋 Changeset detected

Latest commit: 0c48456

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]

Merging this PR will degrade performance by 36.55%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

❌ 2 regressed benchmarks
✅ 158 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
❌	projection derive: write one NESTED field (reference)	222 µs	523.2 µs	-57.56%
❌	memo + sync render effect only (reference)	82.1 ms	86.6 ms	-5.13%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing brenelz:fix/nested-render-effect-cleanup-3404 (0c48456) with next (50323b4)}