ci probe: tier-2 config-brand in isolation (do not merge)

[ryansolid]

Single-patch attribution probe for #2905's CodSpeed regressions. Zero-diff probe (#2906) came back clean, so the regressions are real; this measures the config-brand consolidation alone. Will close after CodSpeed reports.

🤖 Generated with Claude Code

[changeset-bot]

⚠️ No Changeset found

Latest commit: 2f7ffea

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[github-actions]

size-limit report 📦

Path	Size
signals: core floor (createSignal/Memo/Effect/Root/flush)	6.66 KB (-0.3% 🔽)
signals: + createStore	11.27 KB (-0.13% 🔽)
signals: + isPending/latest	8.18 KB (-0.44% 🔽)
app: render + one signal (the simple-app floor)	9.15 KB (-0.48% 🔽)
app: CSR with Show/For/Loading/Errored/lazy	11.19 KB (-0.32% 🔽)

[coveralls]

Coverage Report for CI Build 29616815870

Warning

No base build found for commit 66a6c13 on next.
Coverage changes can't be calculated without a base build.
If a base build is processing, this comment will update automatically when it completes.

Coverage: 74.74%

Details

• Patch coverage: No coverable lines changed in this PR.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

Requires a base build to compare against. How to fix this →

---

Coverage Stats

Relevant Lines:	596
Covered Lines:	477
Line Coverage:	80.03%
Relevant Branches:	461
Covered Branches:	313
Branch Coverage:	67.9%
Branches in Coverage %:	Yes
Coverage Strength:	14.28 hits per line

---

💛 - Coveralls

[codspeed-hq]

Merging this PR will degrade performance by 6.9%

⚠️ 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

❌ 1 regressed benchmark
✅ 120 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
❌	merge	165.2 µs	177.5 µs	-6.9%

Tip

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

---

_{Comparing probe/tier2-config-brand (2f7ffea) with next (66a6c13)}

[ryansolid]

Probe served its purpose: guilty — config-brand alone reproduces merge −7% and carries sub-threshold −3..4% on update1to1/propagation (dashboard), making it the driver of both #2905 regressions. The change is load-neutral by inspection and byte-flat in an isolated merge harness; the diffuse cross-bench signature points at shared-process JIT/IC state redistribution from the hasOverride shape change. Pulled from #2905; to be redesigned shape-stably (dedicated boolean in the node creation literal rather than a _config RMW).