Resend a phone code on Textbridge's second UK route when no receipt comes in 90 s

After Saturday at Northgate (codes held 45 minutes, people at the gate, SUP-1222). Textbridge confirmed on Friday, answering Elif's question, that a second UK route can be requested per message.

Acceptance criteria

• No delivery receipt 90 s after Textbridge accepted a code to a UK number: send the same code again on the second route.
• Log both sends. The code stays valid 10 minutes from the first send.
• Never more than one resend per code.

Target 23 October.