feat(signals): ABANDONED_FLIGHTS, FALLBACK_FLASH, STACKED_HOLDS as findings

[ryansolid]

Item 4 of documentation/plans/responsiveness-findings-plan.md.

feedback() already counts abandoned flights per source, fallback flashes per boundary and holds per interaction — but only for a consumer that imports the fold and reads the tables afterwards. These are the same facts emitted on the diagnostics channel at a threshold, while they happen, so an issue tracker hears them without shipping the fold.

• ABANDONED_FLIGHTS (warn) — one async source abandoned count flights within windowMs (defaults 3 / 1000 ms), each superseded by the next before it landed: the request-per-keystroke signature. Once per window per source; the window is an engine WeakMap, so the node carries nothing.
• FALLBACK_FLASH (info) — a Loading fallback displayed and hidden inside FALLBACK_FLASH_MS (150 ms, now exported and shared with the fold). Judged at hide on the display clock the fallback record and feedback().fallbacks[].flashes already use; the open is kept for the check even with no fold and no record listener.
• STACKED_HOLDS (warn) — count or more interactions (default 3) were waiting in one hold when it committed. Counted over the open interactions at hold settle, before settleInteractionsHeld releases them; data is the hold's plus interactions.

Options

abandonedFlights: { count, windowMs } | false, fallbackFlashes: boolean, stackedHolds: { count } | false — merged most-demanding like the rest (demanding handles them generically: count min, windowMs max, boolean OR). Not under checks: these are verdicts on records, not cost accounting, same as holds/longHolds.

Public API

• DiagnosticCode gains "ABANDONED_FLIGHTS", "FALLBACK_FLASH", "STACKED_HOLDS".
• AttributionOptions gains the three options above.
• FALLBACK_FLASH_MS exported from solid-js/attribution (was a private constant in the feedback fold).

Size

Engine +756 B (29.00 → 29.80 KB), mostly the three repair texts. The tier moved +35 B with byte-count-identical core artifacts: the package-wide terser nameCache runs files in sorted order and core/attribution.js precedes core/core.js, so any change to _-property usage in the engine reassigns the short names the core's files receive — brotli drift, not code. Noted in the cap (17.45 → 17.50 KB); worth knowing for every engine PR. #3604 and #3607 also move the engine cap; whichever merges last re-measures.

Tests: 6 new (fires-once-per-window / below-count-and-disabled for each). signals 3602 / web 898 / solid 685 green.

[changeset-bot]

🦋 Changeset detected

Latest commit: 3d5cd0c

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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[coveralls]

Coverage Report for CI Build 35963056164

Coverage remained the same at 73.134%

Details

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

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Relevant Lines:	1142
Covered Lines:	883
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[codspeed]

Merging this PR will not alter performance

✅ 176 untouched benchmarks
⏩ 3 skipped benchmarks¹

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_{Comparing feat/feedback-findings (3d5cd0c) with next (886850b)}

Footnotes

1. 3 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩