feat(platform): add device info and network summary support

This adds DeviceInfo to the Platform interface and implements it for Android, iOS, and JVM, including battery level and active network summary where available.

Co-authored-by: Junie <junie@jetbrains.com>

shared/src/commonMain/kotlin/com/vnidrop/app/Platform.kt

@@ -4,6 +4,15 @@ interface Platform {
 	val name: String
 	val defaultCoreDataDir: String
 	val defaultReceiveDir: String
+	val deviceInfo: DeviceInfo
 }
 
+data class DeviceInfo(
+	val deviceName: String?,
+	val deviceModel: String?,
+	val operatingSystem: String,
+	val network: String?,
+	val batteryLevel: String?,
+)
+
 expect fun getPlatform(): Platform