OP_KEY_REQUEST replays

[taoeffect]

Problem

See discussion here: https://github.com/okTurtles/shelterprotocol.net/issues/5#issuecomment-2332198606

Solution

1. Figure out whether this is a serious problem or not.
2. Discuss solutions and see whether the solutions result in more problems or not.
3. If a meaningful problem is identified, and a satisfactory solution is found, implement it.