Add a live, #[ignore]d end-to-end test proving a HarnessRelay in serverless
mode (as a managed agent runs) receives + decrypts a NIP-17 gift-wrapped
message over a real public relay and surfaces it via next_event() with the
verified sender preserved. Matches the repo's e2e convention (RELAY_URL env,
default damus). Also wire RELAY_URL into the existing serverless live tests so
they aren't hardcoded to damus.
Michael Neale
a568920cf9