[BUG] getEventExpiration() accepts expiration timestamp 0 as valid and rejects valid year 2287+ timestamps #707

Describe the bug

In src/utils/event.ts, getEventExpiration() validates the NIP-40 expiration tag with a Math.log10() bounds check:

if (Number.isSafeInteger(expirationTime) && Math.log10(expirationTime) < 10) {
  return expirationTime
}

To Reproduce

Steps to reproduce the behavior:

1. Publish an event with an expiration tag of 0, e.g. ["expiration", "0"].
2. Observe the relay treats it as a validing/ignoring it.
3. Publish an event with an expiration tag > 9999999999, e.g. ["expiration", "10000000000"].
4. Observe the expiration is silently drores.

Screenshots

N/A

System

• OS: Linux
• Platform: Docker
• Version: 3.0.0

Logs

N/A — no error is logged; the timestamp ided.

Additional context

getEventExpiration() is at src/utils/evenis at src/utils/event.ts:256). Its result feeds addExpirationMetadata() in src/handlers/event-message-handler.ts, so discard-far-future cases affect real event expiry behavior.