fix(calendar): hide linked Google Calendar events

[Pedrohgv]

Summary

Fixes #1451 by suppressing the Google Calendar copy of a TaskNotes task in Calendar and Mini Calendar views.

• Filters only events from the configured TaskNotes Google export calendar.
• Matches direct event IDs, detached recurring exceptions, and expanded instances of an exported recurring series.
• Keeps unrelated events and events from other Google calendars visible.

Tests

• npx jest tests/unit/bases/calendarExternalEvents.test.ts
• npm run lint:ts
• npm run lint:review-types
• npm run lint:architecture
• npm run build

The full unit suite has pre-existing failures on the base branch related to generated releaseNotes imports and a date-sensitive calendar-mutation test; this change introduces no additional failures.