Revert "hogar compartido: colaboracion entre cuentas sobre Firestore"

El hogar compartido cambia donde viven los datos, asi que se va a la 3.0 y la
2.x queda para correcciones. El trabajo sigue vivo en la rama 3.0.0 (163fd60).

Importante para esta rama: esto tambien retira el entitlement
com.apple.developer.applesignin, que sin la capability marcada en el App ID
habria roto la firma al subir la 2.1.1 a TestFlight.

This reverts commit 163fd60.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013su1ttRiMeMYxkZJ1Y3246

MealMood/ContentView.swift

@@ -33,11 +33,6 @@ struct ContentView: View {
         // Activate WatchConnectivity as early as possible so the first widget
         // refresh doesn't race the session activation.
         .onAppear { WatchSyncService.shared.activate() }
-        // 2.2: household content syncs through Firestore instead of CloudKit.
-        .onAppear {
-            HouseholdService.shared.start()
-            HouseholdSyncService.shared.start(context: context)
-        }
         // This is the most reliable way to catch a purchase even if the app was
         // interrupted during the payment flow.
         .task {