fix: update attendee workflows with new meeting URL on booking reassignment

[joeauyeung]

What does this PR do?

When a booking is reassigned to a new host in round-robin scheduling, the meeting URL changes but previously only EMAIL_HOST workflows were updated with the new URL. This caused attendees to receive workflow notifications (emails, SMS, WhatsApp) containing the old host's meeting link.

This PR extends handleWorkflowsUpdate to also reschedule:

• EMAIL_ATTENDEE workflows
• SMS_ATTENDEE workflows
• WHATSAPP_ATTENDEE workflows

The fix follows the existing pattern: create a new reminder with updated event data (including the new meeting URL), then delete the old reminder.

Note: EMAIL_ADDRESS, SMS_NUMBER, and WHATSAPP_NUMBER workflows are intentionally not updated, as these are generic broadcast workflows that may not be booking-participant-specific.

Visual Demo (For contributors especially)

N/A - This is a backend change affecting workflow notification content. The fix ensures the {meeting_url} variable in workflow templates resolves to the correct URL after reassignment.

Mandatory Tasks (DO NOT REMOVE)

• I have self-reviewed the code (A decent size PR without self-review might be rejected).
• I have updated the developer docs in /docs if this PR makes changes that would require a documentation change. N/A - no documentation changes needed.
• I confirm automated tests are in place that prove my fix is effective or that my feature works.

How should this be tested?

1. Create a round-robin team event type with workflows configured:
   • An EMAIL_ATTENDEE workflow with {meeting_url} in the template
   • An SMS_ATTENDEE workflow with {meeting_url} in the template (if SMS is configured)
2. Book the event (assigns to Host A)
3. Manually reassign the booking to Host B
4. Verify the workflow reminders sent to attendees contain Host B's meeting URL, not Host A's

Human Review Checklist

• Verify the delete is always called even when the new reminder can't be created (e.g., missing phone number) - this is intentional to clean up stale reminders
• Confirm using evt.attendees?.[0] for attendee info is correct for reassignment scenarios
• Check if seatReferenceUid should be passed to SMS/WhatsApp schedulers

Checklist

• I have read the contributing guide
• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have checked if my changes generate no new warnings

---

Link to Devin run: https://app.devin.ai/sessions/ac8247cbf0b444d59a142cf2cab00ed7
Requested by: [email protected] (@joeauyeung)

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR that start with 'DevinAI' or '@devin'.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring