chore: Disables syncing of calendarList on overlay calendar fetch

[emrysal]

Summary by cubic

Disable calendar syncing when opening the Overlay Calendar to reduce load time and avoid unnecessary external calls. Adds a skipSync flag across client and server and tightens types and UI around the overlay flow.

• Refactors
  • Pass skipSync: true in connectedCalendars TRPC query and plumb through handler and schema.
  • Update getConnectedDestinationCalendars to respect skipSync and avoid third‑party sync.
  • Consolidate calendar types (ToggledConnectedCalendars, WrappedBookerPropsMain.calendars) and adjust signatures.
  • Simplify render logic in Booker and Overlay components; return null where appropriate.
  • Overlay settings modal uses Next/Image, improves labels, and cleans imports.

^{Written for commit 83f966c. Summary will update on new commits.}