Review follow-up:
- tickets.confirmation-email.ts: a failed .ics generation was swallowed
silently; log a warning (the email still goes out without the
attachment)
- test/common/salesforce.client.test.ts: direct coverage for the shared
client's token cache and retry-once-on-401 (previously exercised only
indirectly through the newsletter sync test)
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
