[6.x] Fix 2FA setup modal not re-opening

[duncanmcclean]

This pull request fixes an issue where the 2FA setup modal wouldn't re-open after dismissing it by clicking on the modal's overlay.

Noticed this yesterday while testing something.

[jasonvarga]

via AI:

Nice fix for the re-open bug — switching to v-model:open is the right call. However, I think the unconditional watcher introduces a regression in the confirm flow.

When confirm() succeeds, it sets setupModalOpen.value = false before setting recoveryCodesModalOpen.value = true. The watcher fires and emits close to the parent:

watch(setupModalOpen, (open) => {
    if (!open) emit('close');
});

The parent handles @close="setupModalOpen = false", which makes its v-if="setupModalOpen" false, unmounting the entire <TwoFactorSetup> component — including the <TwoFactorRecoveryCodesModal> that was about to render. The user would confirm their code but never see their recovery codes.

A minimal fix would be to guard the watcher so it only emits close when we're not transitioning to the recovery codes step:

watch(setupModalOpen, (open) => {
    if (!open && !recoveryCodesModalOpen.value) emit('close');
});

Both ref mutations in confirm() are synchronous, so recoveryCodesModalOpen is already true by the time the watcher callback runs.