docs(signals): U-5 filed as #4071, deferred past 2.0

[ryansolid]

Summary

Before: the U-5 row in OPEN-QUESTIONS.md listed U-5 as still to build.

After: the U-5 row says U-5 is filed as #4071 and deferred past 2.0, with the prototype's cost (+179 B minified on the core floor, two pinned orders broken). The answer line is updated to match. The F2 pin's comment points at the issue, and the pin stays it.fails.

The maintainer chose to drop U-5 from the build order and file it, because a fix sits on the core seam that every app pays for.

How did you test this change?

Docs and a test comment only. node packages/signals/scripts/rules-index.mjs regenerates the index with no change, and prettier is clean.

🤖 Generated with Claude Code

https://claude.ai/code/session_011JxYhsd8CeAgCp6h5DU8ic

---

Generated by Claude Code

[changeset-bot]

⚠️ No Changeset found

Latest commit: baf3270

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 (brotli, eager entry chunk)

scenario	head	vs base	minified vs base	minified vs recorded	cap		lazy chunks (not counted)
signals: core floor (createSignal/Memo/Effect/Root/flush)	7.47 KB	0 B	0 B	+19 B	7.48 KB	✅
signals: + createStore	14.90 KB	0 B	0 B	+6 B	14.94 KB	✅
signals: + isPending/latest	9.77 KB	0 B	0 B	+18 B	9.77 KB	⚠️ over by 3 B, 2 B minified headroom
app: render + one signal (the simple-app floor)	9.98 KB	0 B	0 B	+18 B	9.98 KB	⚠️ over by 2 B, 2 B minified headroom
app: hydrating (no stores) with Show/For/Loading/Errored/lazy	18.09 KB	0 B	0 B	−9 B	18.09 KB	✅	lazy-page.js 0.04 KB
app: hydrating + every store primitive family	29.65 KB	0 B	0 B	−6 B	29.65 KB	⚠️ over by 4 B, 26 B minified headroom	lazy-page.js 0.04 KB
app: CSR with Show/For/Loading/Errored/lazy	13.20 KB	0 B	0 B	−69 B	13.20 KB	✅	lazy-page.js 0.04 KB
app: CSR, observe tier (same app on the observe artifacts)	14.76 KB	0 B	0 B	−67 B	14.79 KB	✅	lazy-page.js 0.04 KB
app: CSR, observe tier + attribution engine enabled	29.40 KB	0 B	0 B	−66 B	29.38 KB	⚠️ over by 18 B, 86 B minified headroom	lazy-page.js 0.04 KB
app: compiled floor (one template, one text hole, one delegated click)	10.19 KB	0 B	0 B	+18 B	10.17 KB	⚠️ over by 17 B, 2 B minified headroom
app: compiled CSR (JSX todo app: spread/merge/omit, events, class/style, keyed For, Show, Loading + lazy, store)	25.85 KB	0 B	0 B	−67 B	25.92 KB	✅	stats.js 0.18 KB
app: compiled hydrating (the same JSX todo app through hydrate(), compiled hydratable)	31.78 KB	0 B	0 B	−6 B	31.78 KB	⚠️ over by 1 B, 26 B minified headroom	stats.js 0.20 KB
frames: eager client consumer (frames client + transport, lazy codec)	11.54 KB	0 B	0 B	0 B	11.54 KB	✅
page: base server components (hydrating + dynamic + frames + sf reference)	34.33 KB	0 B	0 B	−932 B	34.33 KB	✅	assets.js 0.78 KB, bind.js 1.83 KB, decode.js 6.23 KB, lazy-page.js 0.04 KB, regions.js 0.80 KB, trace.js 9.02 KB, wire.js 0.93 KB
page: live server components (base + live/GET + action + isPending/latest)	38.15 KB	0 B	0 B	−996 B	38.15 KB	✅	assets.js 0.78 KB, bind.js 1.83 KB, decode.js 6.23 KB, lazy-page.js 0.04 KB, regions.js 0.80 KB, trace.js 9.00 KB, wire.js 0.93 KB
page: compiled base server components (the base page as JSX: templates with class/style/attributes/events, For/Show; no spread)	35.18 KB	0 B	0 B	−2022 B	35.66 KB	✅	assets.js 0.78 KB, bind.js 1.83 KB, decode.js 6.23 KB, regions.js 0.80 KB, sc-comments.js 0.20 KB, trace.js 8.98 KB, wire.js 0.93 KB
page: compiled live server components (the compiled base page + live/GET + action + isPending/latest)	40.84 KB	0 B	0 B	−2010 B	41.21 KB	✅	eager (counted): web.js 21.67 KB; assets.js 0.78 KB, bind.js 1.84 KB, decode.js 6.23 KB, regions.js 0.79 KB, sc-comments.js 0.19 KB, trace.js 8.98 KB, wire.js 0.93 KB
page: base + router (base page + @solidjs/router: createRouter, two routes, preload, useNavigate)	41.73 KB	0 B	0 B	−938 B	41.79 KB	✅	assets.js 0.78 KB, bind.js 1.85 KB, decode.js 6.23 KB, lazy-page.js 0.04 KB, regions.js 0.80 KB, server.js 1.02 KB, serverForms.js 3.58 KB, trace.js 9.02 KB, wire.js 0.94 KB
page: live + router (live page + @solidjs/router: createRouter, two routes, preload, useNavigate)	47.50 KB	0 B	0 B	−932 B	47.49 KB	⚠️ over by 7 B, 952 B minified headroom	eager (counted): client.js 27.90 KB; assets.js 0.78 KB, bind.js 1.84 KB, decode.js 6.23 KB, lazy-page.js 0.04 KB, regions.js 0.81 KB, server.js 1.02 KB, serverForms.js 3.30 KB, trace.js 9.00 KB, wire.js 0.94 KB
server: floor (getRequestEvent + isServer)	1.33 KB	0 B	0 B	0 B	1.34 KB	✅
server: renderToString (the server-render floor)	20.57 KB	0 B	0 B	0 B	20.58 KB	✅

⚠️ Over the brotli cap within the minified allowance (passes)

• signals: + isPending/latest: over brotli cap by 3 B; minified 27,465 B vs 27,447 B recorded with the cap (+18 B) — 2 B of the 20 B minified allowance left; +0 B minified over this PR's base
• app: render + one signal (the simple-app floor): over brotli cap by 2 B; minified 27,963 B vs 27,945 B recorded with the cap (+18 B) — 2 B of the 20 B minified allowance left; +0 B minified over this PR's base
• app: hydrating + every store primitive family: over brotli cap by 4 B; minified 93,708 B vs 93,714 B recorded with the cap (−6 B) — 26 B of the 20 B minified allowance left; +0 B minified over this PR's base
• app: CSR, observe tier + attribution engine enabled: over brotli cap by 18 B; minified 88,264 B vs 88,330 B recorded with the cap (−66 B) — 86 B of the 20 B minified allowance left; +0 B minified over this PR's base
• app: compiled floor (one template, one text hole, one delegated click): over brotli cap by 17 B; minified 28,493 B vs 28,475 B recorded with the cap (+18 B) — 2 B of the 20 B minified allowance left; +0 B minified over this PR's base
• app: compiled hydrating (the same JSX todo app through hydrate(), compiled hydratable): over brotli cap by 1 B; minified 101,332 B vs 101,338 B recorded with the cap (−6 B) — 26 B of the 20 B minified allowance left; +0 B minified over this PR's base
• page: live + router (live page + @solidjs/router: createRouter, two routes, preload, useNavigate): over brotli cap by 7 B; minified 143,192 B vs 144,124 B recorded with the cap (−932 B) — 952 B of the 20 B minified allowance left; +0 B minified over this PR's base

_{Bundled with Rolldown (what Vite ships), brotli q11, decimal KB. A scenario fails only when it is over its brotli cap and its minified size is more than 20 B over the minified recorded with the cap; over the cap within that allowance is brotli layout noise and passes with a warning. Caps and their recorded minified in scripts/size/scenarios.js; the floor and page caps in floor-caps.json are frozen (lower only, or Size-Exception: in the PR body). npm run ratchet lowers caps per RC; it never raises one (scripts/size/README.md).}

[coveralls]

Coverage Report for CI Build 38646238809

Warning

Build has drifted: This PR's base is out of sync with its target branch, so coverage data may include unrelated changes.
Quick fix: rebase this PR. Learn more →

Coverage remained the same at 77.515%

Details

• Coverage remained the same as the base build.
• Patch coverage: No coverable lines changed in this PR.
• No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

---

Coverage Stats

Relevant Lines:	1326
Covered Lines:	1084
Line Coverage:	81.75%
Relevant Branches:	1040
Covered Branches:	750
Branch Coverage:	72.12%
Branches in Coverage %:	Yes
Coverage Strength:	27.41 hits per line

---

💛 - Coveralls

[codspeed]

Merging this PR will improve performance by 6.78%

⚠️ 2 benchmarks spent significant time in system calls

System calls cannot be consistently instrumented, so they are not included in the measure, which understates the real cost. Please switch to the Walltime instrument to accurately measure system calls.

Measurement and system calls

• readAllowed
• propagation:diamond

⚠️ 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 improved benchmark
✅ 194 untouched benchmarks

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
⚡	memo + sync render effect only (reference)	30.6 ms	28.6 ms	+6.78%

Tip

Curious why performance improved? Comment @codspeedbot explain why performance improved on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing docs/u5-filed (baf3270) with next (fb8558c)}