Google Calendar MCP: `guestsCanModify` field missing from all event responses

Description:

The guestsCanModify field is absent from all events returned by both list_events and get_event — including events where the authenticated user is the organizer and could have set the field themselves.

Expected behavior:
When guestsCanModify is set to true on a Google Calendar event, the field should appear in the MCP response (e.g., "guestsCanModify": true). When false, it can be omitted (the Google Calendar API omits it when false by default).

Actual behavior:
guestsCanModify is absent from 100% of events across a 30-day fetch (~hundreds of events), including organizer-owned events. Querying list_events and get_event for the same event both return no guestsCanModify field.

Impact:
Any tool using this field to determine whether the authenticated user can modify an event (a common pattern) will incorrectly treat all non-organizer events as read-only, even when the organizer has granted guests modify access.

Steps to reproduce:

1. Create an event and enable "Guests can modify event"
2. Call list_events or get_event for that event
3. Observe that guestsCanModify is absent from the response

Environment: claude.ai Google Calendar MCP connector (mcp__claude_ai_Google_Calendar)