Use forkScoped for background upstream refresh

- replace `Effect.forkDetach` with `Effect.forkScoped` when refreshing checked-out branch upstream refs
- keep checkout responsive while ensuring the background task stays tied to scope lifecycle
991dd05e72Julius Marminge committed on 3/2/2026, 7:24:22 AMparent96bf54e
1 file changedLine totals unavailable