feat(apple): native SwiftUI app for iOS and macOS

Add a native SwiftUI VniDrop app (Send/Receive/Settings) talking to the
Rust core via generated UniFFI Swift bindings, plus the uniffi-bindgen
helper crate. iOS uses a TabView, macOS a NavigationSplitView sidebar.

apple/VniDrop/Platform/AppDependencies+iOS.swift

@@ -0,0 +1,50 @@
+#if os(iOS)
+import Foundation
+import UIKit
+
+/// Builds the iOS dependency graph, ported from `rememberIosAppDependencies`.
+@MainActor
+func makeAppDependencies(externalInvitations: ExternalInvitationController) -> AppDependencies {
+	let device = UIDevice.current
+	let version = Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as? String ?? "0.1.0"
+	let env = PlatformEnvironment(
+		name: "\(device.systemName) \(device.systemVersion)",
+		appVersion: version,
+		defaultCoreDataDir: applicationDataDirectory(),
+		defaultUsername: device.name.isEmpty ? "Receiver" : device.name
+	)
+	return AppDependencies(
+		environment: env,
+		deviceInfoProvider: IosDeviceInfoProvider(),
+		fileSystemService: IosFileSystemService(),
+		notificationService: LocalNotificationService(),
+		externalInvitations: externalInvitations
+	)
+}
+
+private func applicationDataDirectory() -> String {
+	let base = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask).first!
+	return base.appendingPathComponent("VniDrop").path
+}
+
+private struct IosDeviceInfoProvider: DeviceInfoProvider {
+	@MainActor
+	func load() async -> DeviceInfo {
+		let device = UIDevice.current
+		let battery: String? = {
+			let wasMonitoring = device.isBatteryMonitoringEnabled
+			device.isBatteryMonitoringEnabled = true
+			defer { device.isBatteryMonitoringEnabled = wasMonitoring }
+			let level = device.batteryLevel
+			return level >= 0 ? "\(Int(level * 100))%" : nil
+		}()
+		return DeviceInfo(
+			deviceName: device.name,
+			deviceModel: device.model,
+			operatingSystem: "\(device.systemName) \(device.systemVersion)",
+			network: nil,
+			batteryLevel: battery
+		)
+	}
+}
+#endif