fix: improve UI feedback for disconnect by setting state immediately

- Set extensionStateText to 'Disconnecting' immediately when disconnect is pressed - Call checkExtensionState() immediately after stop() to update UI without waiting for 30s periodic check - Provides immediate UI feedback similar to connect() behavior - Improves user experience by showing disconnect state immediately instead of delayed update

Author: devc0der

NetBird/Source/App/ViewModels/MainViewModel.swift

@@ -156,7 +156,14 @@ class ViewModel: ObservableObject {
  DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
  self.buttonLock = false
  }
+ // Set UI state to "Disconnecting" immediately for better UX
+ self.extensionStateText = "Disconnecting"
  self.networkExtensionAdapter.stop()
+ 
+ // Check extension state immediately to update UI
+ // This ensures UI updates immediately when extension becomes disconnected
+ // instead of waiting for the 30s periodic check
+ self.checkExtensionState()
  }
  }