Don't retry a pairing failure on returning to the app; README installs the docker client

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

ios/FrameControl/App/AppModel.swift

@@ -252,7 +252,8 @@ final class AppModel: ObservableObject {
                 if (!ok || server?.exited != nil), mine == attempt { await connect() }
             }
         case .failed:
-            if settings != nil { Task { await connect() } }
+            // A changed identity or a refused login needs the user, not another try.
+            if settings != nil, !needsPairing { Task { await connect() } }
         default:
             break
         }