The sorted report finally named it: `table.api-tokens__table` at 833px
wide, with its `.visually-hidden` heading reaching right=737 — exactly
the document's scrollWidth. Same mechanism as the sessions table, a
second table I had not wrapped.
Locally the API-tokens table was empty and therefore narrow, which is why
this only ever appeared in CI. With a token present it reproduces:
without the wrapper 345px of page overflow, with it none.
The feed-token table gets the same treatment — it is built the same way
and would fail as soon as someone holds a feed token with a long name.
The "[in fitting scroller]" marker in the report is misleading for these:
`main.main` is a scroller, but it is `position: static`, so it never
clipped the absolutely positioned heading. Only a positioned ancestor
does — which is what `.table-scroll` now is.
Verified locally against a real stack, with a wide token table present:
reflow guard green, whole a11y pack green in both colour schemes.
Claude Opus 5
69882ecbea