Expose the edited guest name (custom thread name) via Public API and MCP

Please expose the edited guest name (the one hosts set at the top of a conversation thread in the inbox) through the Public API and MCP.

Right now, hosts often edit a guest's name in the thread, for example changing "Katherine" to "Katie" when a guest asks to be called that, or fixing Booking.com reservations where the first and last names arrive transposed (which happens on roughly a third of Booking.com bookings). That edited name is used everywhere inside Hospitable (inbox, automated messages, guest portal), but the Public API and MCP still return only the original, uncorrected name from the booking channel.

This is especially painful on Booking.com, since Booking.com has no "preferred name" fallback like Airbnb, and the raw name is often transposed. In that case the thread edit is the only corrected version of the guest's name, and there is currently no way to retrieve it externally.

As a result, any AI agent, CRM sync, guest-messaging workflow, or reporting layer built on top of Hospitable ends up using the wrong (or reversed) name, undoing the correction the host already made.

What we would like:

Return the edited guest name on the reservation and guest responses in the Public API and MCP. Ideally, also return a single "display name" that follows the same order Hospitable uses internally (edited thread name first, then channel preferred name, then the raw channel name), so integrators do not have to rebuild that logic themselves.