Add in-game settings menu with web panel sync

Features:
- SettingsActivity accessible via Menu button (keycode 82)
- Configure server URL and mode (online/offline) in-game
- Test connection before saving settings
- Switch to offline mode with one tap
- Sync settings from web admin panel
- Real-time status messages with emoji indicators

Implementation:
- Created 13 SettingsActivity Smali files (main + inner classes)
- Created activity_settings.xml UI layout
- Added SettingsActivity to AndroidManifest.xml (portrait mode)
- Modified MainActivity.smali to handle Menu button press
- Integrated with existing ServerManager for Nimble SDK overrides
- Settings stored in SharedPreferences (rr3_server_config.xml)

APK:
- Built and signed: RR3-v14-Settings-Menu.apk (103 MB)
- Keystore: rr3-release.keystore (alias: rr3key)
- Ready for distribution

Related server changes:
- ServerSettingsController.cs with 3 API endpoints
- DeviceSettings.cshtml admin page
- UserSettings database model and migration

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

AndroidManifest.xml

@@ -97,6 +97,7 @@
             </intent-filter>
         </activity>
         <activity android:alwaysRetainTaskState="true" android:configChanges="keyboard|keyboardHidden|orientation|screenSize|smallestScreenSize|uiMode" android:hardwareAccelerated="true" android:label="@string/app_name" android:launchMode="singleTask" android:name="com.firemint.realracing.MainActivity" android:screenOrientation="sensorLandscape" android:theme="@style/splashScreenTheme"/>
+        <activity android:name="com.firemint.realracing.SettingsActivity" android:label="RR3 Settings" android:theme="@android:style/Theme.Black.NoTitleBar" android:screenOrientation="portrait"/>
         <property android:name="android.adservices.AD_SERVICES_CONFIG" android:resource="@xml/gma_ad_services_config"/>
         <provider android:authorities="com.ea.games.r3_row.fileprovider" android:exported="false" android:grantUriPermissions="true" android:name="androidx.core.content.FileProvider">
             <meta-data android:name="android.support.FILE_PROVIDER_PATHS" android:resource="@xml/file_paths"/>