Wrap all bot.api.sendXxx() media calls in delivery.ts with error handler
that logs failures before re-throwing. This ensures network failures are
properly logged with context instead of causing unhandled promise rejections
that crash the gateway.
Also wrap the fetch() call in telegram onboarding with try/catch to
gracefully handle network errors during username lookup.
Fixes#2487
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
