Custom Calendar Views (e.g., "Work View", "Vacation View")

Please add support for custom calendar views, allowing users to group and toggle specific calendars into named views such as "Work", "Personal", or "Vacation".

When users manage many calendars (e.g., work, team, project, personal, family), the current view can become cluttered and hard to navigate. A helpful solution would be to let users create custom calendar views that display only a selected subset of calendars.

Example Use Cases:

• Work View: Shows only calendars related to job, meetings, and team events.

• Vacation View: Hides work calendars and shows only personal, family, and travel-related calendars.

• Focus Mode: A minimal view with only essential calendars visible.

Functionality Suggestions:

• Users can create and name multiple views.

• Each view can store a custom selection of visible calendars.

• Quick toggle between views from the main interface.

• Optionally, persist selected view between sessions.