* fix: filter out Google system calendars from calendar list
Google system calendars (holidays, birthdays) don't return proper
free/busy information, making them useless for availability checking.
This change filters them out from the listCalendars() method so users
won't see these calendars as selectable options.
Filtered calendar types:
- Holiday calendars (#holiday@group.v.calendar.google.com)
- Birthdays/contacts calendar (#contacts@group.v.calendar.google.com)
Co-Authored-By: Volnei Munhoz <volnei.munhoz@gmail.com>
* test: add tests for Google system calendar filtering
Tests verify that listCalendars() correctly filters out:
- Holiday calendars (#holiday@group.v.calendar.google.com)
- Birthdays/contacts calendar (#contacts@group.v.calendar.google.com)
Test cases cover:
- Filtering holiday calendars
- Filtering birthdays calendar
- Mixed calendars (keeping regular, filtering system)
- All system calendars (returns empty array)
- Null/undefined calendar IDs
- Various international holiday calendar formats
Co-Authored-By: Volnei Munhoz <volnei.munhoz@gmail.com>
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Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
