inbox-bubble: a mount without KAITO shows no status line; data-title is aria-only, so a site cannot put its one sentence under the site name

[cverorg]

Seen 2026-09-08 on a site mounted with kind=ext and no data-kaito: the panel shows the site name, ×, the form and Send — no status line at all. With KAITO on, the status line renders statusDefault ('[AI] answers first, a person reads what you send on'). The per-mount data-title only feeds the dialog's aria-label (ruling 2026-09-07, bubble-copy lane §一), so a site that wants one visible sentence ('a person reads what you send') has no attribute to set it. Proposal: in no-KAITO mode render a status line with a no-AI variant per locale ('A person reads what you send' / 「真人會看」), overridable by a new data-status attribute (escaped, one line, 80-char cap); keep data-title as aria-only but document that.