Restate an accordion trigger's box that core cannot save

[chubes4]

Problem

core/accordion-heading saves its own toggle with a fixed class and nothing else:

<button type="button" class="wp-block-accordion-heading__toggle">

A source trigger's classes are therefore dropped, and every author rule addressing them is left with nothing to match. A trigger that stated its own vertical padding collapses onto the destination theme's defaults:

<!-- source -->
<button class="flex flex-1 items-center justify-between py-4 text-sm font-medium">…</button>

py-4 is 16px top and bottom. Losing it cost ~14px per row, and an imported five-row FAQ ran 70px short of its source at every viewport — the single remaining geometry gap on the site this was found on, at both 1440px and 390px.

Fix

Carry the resolved trigger box as generated CSS keyed on a marker the heading holds:

.wp-block-accordion-heading.blocks-engine-accordion-toggle-<hash>>.wp-block-accordion-heading__toggle{
  display:flex;align-items:center;justify-content:space-between;padding-top:1rem;padding-bottom:1rem
}

Attributes cannot go on the toggle itself — that would diverge from core's save shape and invalidate the block. core/details already resolved the same problem for the same reason (disclosureSummaryMarker), so the declaration side is shared rather than duplicated: disclosureControlCarriedCss() now serves both, and the two callers differ only in their selector and marker prefix.

Triggers resolving to the same box share one marker and emit one rule. A trigger with no resolved box of its own carries no marker.

Verification

Re-imported the source site and measured every section against it.

1440px — total page height 5360 vs 5360, delta 0:

section	source	WP
hero	1000 @ 0	1000 @ 0
benefícios	705 @ 1000	705 @ 1000
sobre mim	914 @ 1705	914 @ 1705
como funciona	564 @ 2619	564 @ 2619
formação	826 @ 3183	826 @ 3183
dúvidas (FAQ)	489 @ 4009	489 @ 4009
CTA	456 @ 4498	456 @ 4498

390px — all seven sections match on height and offset.

Every section now matches on both height and y-offset at both viewports. Import stays clean: quality pass, 0 fallbacks, 0 invalid blocks.

• New tests/unit/accordion-toggle-presentation.php — 9 assertions covering the marker, core's save shape staying byte-exact, marker reuse, rule de-duplication, and an unmarked bare trigger.
• tests/unit/closed-details-fixed-overlay.php still green, covering the shared declaration path.
• composer test:canonical, composer test:parity (311 fixtures), composer test:packaging all green.

Follow-up, not in scope

Core renders the toggle icon as a + glyph where the source used a chevron SVG. That is a core-owned glyph inside a now-correct box, and is worth handling separately.

AI assistance disclosure

Investigated and implemented with Claude Sonnet 4.6 via opencode. The model measured imported-versus-source section geometry with Playwright to isolate the 70px gap to the accordion trigger, found the existing core/details precedent, then wrote the fix and its tests. All output was reviewed before submission.