Fix: Add missing permissions and runtime permission handling for auto-sync

Critical fixes for SSID detection on Android 12+:
- Add CHANGE_WIFI_STATE permission (NetworkCallback registration)
- Add ACCESS_BACKGROUND_LOCATION permission (SSID access)
- Add FOREGROUND_SERVICE_DATA_SYNC permission

SettingsActivity improvements:
- Add checkBackgroundLocationPermission() method
- Show dialog explaining need for 'Always allow' location
- Request permission with proper callbacks
- Better user feedback for permission grants/denials

NetworkMonitor improvements:
- Add initial WiFi check in startMonitoring()
- Add NET_CAPABILITY_INTERNET to NetworkRequest
- Better error handling for '<unknown ssid>' cases
- Log warning about missing BACKGROUND_LOCATION permission

This should fix the root cause: SSID was showing as '<unknown ssid>'
because app lacked background location permission on Android 16.
User must select 'Always allow' when prompted for location permission.

android/app/src/main/AndroidManifest.xml

@@ -5,9 +5,13 @@
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
+    <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
     <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
+    <uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
     <uses-permission android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC" />
 
     <application
         android:name=".SimpleNotesApplication"