Update up to 200 guests

Updates run in order and stop on the first refusal. The result reports every requested row as updated, failed, or not attempted. Retry of the same value-setting patches converges, but read after a lost response to locate the stop point. When the couple has enabled room-assignment emails in Stays, assigning a different room also queues an email to the eligible guest on a published site with Stay available. The guest needs their own recorded email and must not have opted out; known under-13 and declined guests are excluded. This is off by default, does not charge the guest, and does not notify previous assignments when enabled. A retry assigning the same room does not create another notice; clearing a room sends no email. Email delivery is asynchronous and may be withheld when the assignment, contact, consent or site access changes.