Do not start Tor or notifications for offline flavor

- Skip `TorManager.init()` and `stats.createNotificationChannel()` in
  Amber.onCreate() for the offline flavor — no relay connections means
  no need for notification channels or Tor initialisation
- Guard `stats.updateNotification()` in `reconnect()` behind the same
  offline check to avoid accessing uninitialised lateinit vars
- Add an early-return guard in `AmberRelayStats.updateNotification()`
  so any call path that reaches it from relay listeners is also safe

https://claude.ai/code/session_014Zqb1AEPPF2RrzmEyPnmei

app/src/main/java/com/greenart7c3/nostrsigner/Amber.kt

@@ -227,8 +227,10 @@ class Amber :
 
         instance = this
 
-        stats.createNotificationChannel()
-        TorManager.init(this)
+        if (!BuildFlavorChecker.isOfflineFlavor()) {
+            stats.createNotificationChannel()
+            TorManager.init(this)
+        }
 
         isStartingAppState.value = true
         isStartingApp.value = true
@@ -371,7 +373,9 @@ class Amber :
             client.connect()
         }
         client.reconnect(wasActive)
-        stats.updateNotification()
+        if (!BuildFlavorChecker.isOfflineFlavor()) {
+            stats.updateNotification()
+        }
     }
 
     fun getDatabase(npub: String): AppDatabase {

app/src/main/java/com/greenart7c3/nostrsigner/relays/AmberRelayStat.kt

@@ -15,6 +15,7 @@ import androidx.core.app.NotificationChannelGroupCompat
 import androidx.core.app.NotificationCompat
 import androidx.core.app.NotificationManagerCompat
 import com.greenart7c3.nostrsigner.Amber
+import com.greenart7c3.nostrsigner.BuildFlavorChecker
 import com.greenart7c3.nostrsigner.MainActivity
 import com.greenart7c3.nostrsigner.R
 import com.greenart7c3.nostrsigner.service.KillSwitchReceiver
@@ -215,6 +216,7 @@ class AmberRelayStats(
     }
 
     fun updateNotification() {
+        if (BuildFlavorChecker.isOfflineFlavor()) return
         val notificationManager = NotificationManagerCompat.from(appContext)
         if (ActivityCompat.checkSelfPermission(appContext, Manifest.permission.POST_NOTIFICATIONS) == PackageManager.PERMISSION_GRANTED) {
             createNotification(