test(web): pin History void→adjust cross-scope close on the success path (#703 PR 3 residual) #709

Found while reviewing #706 (#703 PR 3). Test-only; the shipped code is correct.

Gap. HistoryPage.onVoid force-closes a same-entry adjust dialog on the void's SUCCESS path — if (adjusting?.id === e.id) { setAdjusting(null); dismissDialog("adjust"); } (HistoryPage.tsx:478) — the ungated cross-scope close the owner locked in PR 3 (19-handoff-pr3.md §0 item 3). Its dismissDialog half (mute + end session) is defensive and unreachable by construction: the single flight guard makes an in-flight adjust and a landing void mutually exclusive (recorded as unpinnable in 23-delivery-contract-pr3.md AC-6). But the VISUAL half — the adjust dialog actually closing when its entry is voided from the row — is reachable and untested: dropping the whole line in the success branch keeps the suite green. The 409 twin at :487 is pinned (the pre-existing #491 conflict tests); the success twin is not.

Fix. One test in web/src/routes/HistoryPage.test.tsx: open an entry's adjust dialog, void that same entry from its row (the row void button is reachable behind the backdrop — same shape the existing 409 test uses), let the void succeed → the adjust dialog is gone and entryVoidedMessage shows. Then run the mutant (delete the if (adjusting?.id === e.id) … line at :478) and confirm the new test goes RED; restore; green.

Scope. Test only. No product change. Not part of #703 PR 4 (Users) by owner decision 2026-09-07.