The guest cannot subscribe to the operator's wallet and the existing
booking read needs a wallet invoice key, so a client had no way to wait
for awaiting_payment -> confirmed over HTTP short of polling the invoice
on LNbits core. Add the HTTP twin of the RPC door's chatelet_booking_get:
the 10-char booking id from the quote is the capability, and the response
is public_booking_dict — lifecycle, dates and money only, with the guest's
pubkey/contact and the Lightning/Nostr plumbing stripped.
Closes#18
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>